The Principal Problem

by Sienna Mills

404 pages, Paperback

Published December 28, 2025

About the author

Sienna Mills lives in Atlanta, Georgia, where she spends most of her time dreaming up her next book boyfriend and the woman he’s obsessed with.

If she isn’t writing, she’s with her family.

siennamillsromance.com
sienna@siennamillsromance.com

Reviews

[Ashley Stanford Cone · Rating 5 out of 5]

The Principal Problem is a sweet, small town, enemies to lovers romance that I could not put down. The unresolved trauma and emotional scars that both characters had to work through to find their HEA, while layering in a lot of banter, tender moments, new friendships, found family and of course, all the spice, made for an extremely satisfying read. Even better, there will be more to this series, and I cannot wait.

This was my first time reading Sienna Mills but it will not be my last. Thank you for the ARC read. I absolutely loved Brie and Sawyer’s story and hope to see them again soon..as they continue to ‘paint a beautiful picture together’.

⭐️⭐️⭐️⭐️⭐️

[Ashley · Rating 5 out of 5]

Oh my goodness—I’m so glad I was picked as an arch reader for this book. I truly cannot rave enough about how adorable this book was! It delivered the perfect balance of spice and depth, with incredible character development and meaningful growth throughout. I genuinely couldn’t put it down and ended up staying up far too late because I had to know how it ended.

Sawyer will completely steal your heart one moment and test your patience the next, while Brie keeps you guessing—are we rooting for her, questioning her, or simply relating to her as a girl navigating her emotions?

One thing is certain: Sienna Mills has officially earned a spot on my must-read author list.

[Ashley Brown · Rating 5 out of 5]

I have never to really be known to sit and read a book in one day, until today. This book grabbed me from the first chapter and did not let me go until the end. The only time I put it down was to do a family thing.
Get ready for a crazy ride of love at first sight to school bullying flashbacks. I could relate to the characters in a way I have never been able to in a book. This book is not only a love story for me but a lesson in letting the past go and to see people for who they really are.

[Kay Rose · Rating 5 out of 5]

I was gifted an early copy of this book!

Y'all, when I say I DEVOURED this book, I mean it!!! I didn't want to put it down. The spice was spicyyyyyy and the characters were super likeable and relatable. It had everything: Enemies-to-Lovers, small town romance, YEARNING, he confesses first, I could go on and on.

I already can't wait for the next one. I'm excited to see this story/universe grow.

[Chelsea | Mrs Viking Reads · Rating 5 out of 5]

I stayed up into the early hours of the AM because I physically could not put this book down. Told myself “one more chapter” about twelve times. A liar. A happy liar.

The Principal Problem is enemies-to-lovers done RIGHT. Not the flimsy “we bicker twice and now we’re in love” kind, but the kind with actual history, hurt feelings, misunderstandings, and most importantly - growth. The emotional payoff here? It’s delicious. Its earned. Satisfying in a way that made me want to scream from my rooftop that real love EXISTS and it is MAGICAL.

Sawyer Strong? Peak redeemed golden boy energy. The book lets him reckon with who he was, not just hand-wave it away, and that made every soft moment hit harder. Brie is messy in the best way - human, funny, a little chaotic, and extremely relatable. Their dynamic crackles. He’s steady to her flighty, grounded to her restless, and every time he shows up for her? I about damn near melted into a puddle. A smitten smitten puddle.

And yes. It was HOT. High heat, excellent tension, the kind of chemistry that makes the butterflies in your tummy feel like they’re stirring up a damn hurricane inside you. Add in forced proximity, small-town gossip, public affection that feels a little claiming, and a snowed-in cabin? I was simply unwell.

On top of all that, the writing is gorgeous. Witty, warm, emotionally sharp, and genuinely funny. The small-town setting feels alive, not just a backdrop, and the humour balances the angst perfectly.

Enemies to lovers with substance. Redemption arcs that actually redeem. Steam and heart. This book ate, left no crumbs, and immediately made me want the rest of the Blue Ridge series injected into my veins.

Read it. But cancel your plans first cause you won’t want to put it down 😌

[Molly · Rating 4 out of 5]

This was a really good book. Brie Casey is back in her home town of Blue Ridge after a scandal at the previous school she taught at forced her to leave. She's in Blue Ridge to substitute teach, and when she gets to work that first morning, she finds out the principal is Sawyer Strong, the boy who tormented her all through school. 

The parts with the bullying were hard for me to read, even though I knew there had to be some underlying reasons for them. Brie is rightfully suspicious and leery of Swayer when she returns to town, even when he's trying to be nice to her. One weekend they're stranded together at his cabin during a blizzard and they finally confront their past. I was so glad when Sawyer explained himself, and he acknowledged that there was no excuse for how he acted back then, but that he had worked on himself to change. I love when characters are self aware enough to realize they have a problem and need to fix it.

Brie was still hiding parts of herself though and it took until the end of the book for her to truly open up. Some of the stuff her family went through was so sad, and the bigotry of the small town "elite" was frustrating. There could have been a third act breakup, and while they had a rough moment, Brie and Sawyer actually talked it out. I love when characters communicate like adults! I want to thank ATLast Books and NetGalley for the copy of this book. I voluntarily chose to leave a review.

No third act breakup

4/5 on the Spicy Scale

Bigotry

Misogyny 

Contemporary Romance

[bookedinthepnw · Rating 5 out of 5]

The Principal Problem by Sienna Mills is exactly what you want when you’re craving a small town romance. There’s the big city girl, Brie, who’s forced to come back to Blue Ridge, the small town that’s never quite accepted her, and her childhood nemesis, Sawyer, who’s all grown up and super hot now. He just so happens to be the principal where she works as a substitute teacher, hello forced proximity, and the chemistry is off the charts 🔥. You don’t want to miss this one!

I have to admit that partway through the story, when we had the dual timeline revealing all the torment that Sawyer put Brie through as kids, I wasn’t sure how I was going to be able to forgive him for all his wrongdoings, but Sienna knew what she was writing and made me completely fall in love with Sawyer and I forgave him wholeheartedly. I also loved Brie’s story arc of found family and finally gaining a sense of belonging in her hometown.

Also, can we all just appreciate the gorgeous cover by Chloe Quinn?!

Read for:
🐭 Small town
🐭 Snowed in
🐭 Only one bed (in a cabin)
🐭 Childhood enemies to lovers
🐭 Workplace romance
🐭 Teacher x Principal
🐭 Found family
🐭 Ex Navy SEAL
🐭 He’s her boss
🐭 Only one time
🐭 Forced proximity
🐭 Gray sweatpants
🐭 “Fuck it” moment
🐭 Taco Tursday (not Thursday)
🐭 Humping like (funny) bunnies
🐭 💦 in his pants
🐭 Imaginary hat tips
🐭 Bob Ross underwear

Thank you NetGalley and Sienna Mills for the advance copy to review!

[Prachi M · Rating 4 out of 5]

I’m so grateful to have been selected for the ARC team of The Principal Problem—what a read! I’ve always loved a good enemies-to-lovers story, and this one brings a refreshing twist: the animosity starts all the way back in childhood.
Brie Casey returns to her hometown of Blue Ridge after a scandal at her previous school forces her to leave. Now working as a substitute teacher, she finds herself face-to-face with her childhood bully, who is none other than the school principal, Sawyer Strong. What unfolds isn’t a simple miscommunication trope, but rather a deep exploration of learning how to communicate after years of silence and misunderstanding.
The banter and dialogue are amazingly sharp, natural, and deeply connected to the emotional heartbeat of the story. Every exchange between Brie and Sawyer feels earned, charged, and meaningful. The pacing is spot-on too, with just the right balance of conflict, growth, and resolution.
From start to finish, The Principal Problem delivers an engaging mix of angst and heart. I loved this journey and can’t wait to see what Sienna Mills writes next.

[Courtney Hastings · Rating 5 out of 5]

I received a copy of this for my honest review

Our FMC has packed her whole life into her car and is begrudgingly driving back to her hometown, that she swore she would never come back to. She lost her job at a private school due to rumors making a bad situation worse. Then she accepted a long term substitute teacher position at her old elementary school. She's enough of a wreck that when she finds out who the principal, aka her new boss, is she is ready for the world to just swallow her up. Our MMC is the school principal and didn't know she was going to be the new sub. They both brew up in town together - him the golden boy, mayors son, and her - the daughter of a drink living in the bad part of town. The bigger problem is he tormented her. Made it so she couldn't wait to leave town, and now everything that happens is shrouded in the past. But not everything is what it seems - and sometimes you need a little forced proximity to start tearing down walls and learning both sides of a story.

[Rian Eidson ~ Literary Luna Moth · Rating 5 out of 5]

A beautiful story about redemption, second chances and learning to let others in. The tension between Brie and Sawyer is evident from the first time Sawyer enters a scene. Brie loves to hate him, but also can’t resist him. I loved how they moved from enemies to lovers as it didn’t feel rushed, yet didn’t take forever ever either — it was very much a Goldilocks moment of them making that transition.

Sienna’s writing style was fantastic as it draws you in and holds on. It had me not wanting to put the book down because I wanted to know what was going to happen next. The way Sienna incorporated the flashbacks to Brie and Sawyer’s past was perfection. It gave us the angsty feelings from both POVs while not bogging us down with unnecessary information.

If you’re looking for an enemies to lovers book set in a small town with some delicious spicy scenes, I highly recommend this book!


*Disclaimer*
I received this copy for free as an ARC — I was not paid to review this book, these are my own thoughts and feelings. Thank you to Sienna Mills for the honor to read and review this book!

[Natasha Saunders · Rating 5 out of 5]

The Principal Problem was an addictive, spicy, and emotionally satisfying read that I couldn’t put down.

This story blends childhood enemies-to-lovers with a teacher/principal dynamic. The tension between these two is immediate and delicious. There’s years of unresolved history, sharp banter, and a slow emotional unraveling that makes the payoff incredibly rewarding. The MMC falling first and harder, added such a tender contrast to the heat.

The wintery small town setting, complete with a snowed-in cabin and only one bed, made the atmosphere feel cosy while the romance itself was undeniably steamy. The spice level is high and enhances the emotional connection rather than replacing it.

I also loved the found family elements and was thrilled to learn this is the first book in a series. I’m already excited to return to Blue Ridge and see what’s next.

An easy five star read and one I’d happily recommend to fans of spicy small-town romance.

[Ashley (andtheniwasbookish) · Rating 5 out of 5]

I could not put this book down! I read this beauty in 24 hours. I neglected all responsibilities so that I could read this book full of tension, painful history, and spice that was just off the page steamy (I'm not sure what Sienna Mills put into her spice but WHEW). This book wasn't a miscommunication trope, but it WAS learning how to communicate after years of suppression.


The Principal Problem does come with a heavy bully backstory, so just make sure that you've read those triggers before you get started.

The banter and dialogue in this book is SUPERB! It made sense in the plot, it wasn't forced, I could feel Brie and Sawyer's need for the dialogue every step of the way.

The reader gets great conflict, plot, and resolution in a beautifully timed way. Loved it from start to finish.

I can only say amazing things about this book, and I'm really looking forward to more and more from this author.

overall: highly recommend
spice: open door

[Bernice · Rating 5 out of 5]

This was a very cute read. It had small-town vibes, teenage (into adulthood) angst, and was quite the emotional roller coaster.

In this story, bullying has a new face. It’s the golden boy you’ve grown up with since Kindergarten. After high school graduation, they both go their separate ways, spend almost a decade apart, then find themselves right back together.

Brielle, the female main character, had an incident happen at her previous job, and is vehemently opposed to this happening again; especially when it involves her bully turned coworker.

The Principal Problem was an enemies (bully) to lovers relationship. It had very few triggers and just the right amount of slow burn and spice. The ending had such a cute happily ever after.

I want to thank Sienna Mills for providing me with an ARC of this story and giving me the opportunity to to read, enjoy, and review this book!

[Juli · Rating 5 out of 5]

thanks netgalley for this earc!
The Lit Whisperer’s analysis finds this to be an absolute standout in contemporary romance, earning a glowing 5 stars. I truly couldn’t put it down! It is the perfect mix of cozy reading and the sweetness of Hallmark movies, but with a deliciously spicy relationship that adds a modern edge.
​What really sets this book apart is the depth of the characters' inner struggles. Both their current challenges and the weight of their shared past are written in a way that is absolutely believable and relatable. Sawyer is both sexy and endearing, making him an instant favorite book boyfriend. Meanwhile, Brie is a brilliantly written main character—she is strong and independent, yet her emotional fragility makes her feel so human. I loved every minute of their journey.
​Follow me for more reviews @TheLitWhisperer.

[Sarah · Rating 5 out of 5]

I received The Principal Problem from Sienna as an ARC, and honestly, I’m really upset that this was my first read from her. FOLKS, SHE IS GREAT.
I’m terrible at writing reviews, but here we are. I loved this book. It hit me in the feels as a teacher who spent the first ten years of her career struggling to fit in and find where she belonged. I also connected with Brie, the FMC, as someone who didn’t always have the best times in school thanks to assholes. I may not have found a Sawyer, but I am so glad that Sienna gave Brie Sawyer, and allowed us the chance to watch them connect after Sawyer wasn’t always a great person.
The writing was fanatic. The switches from past to present were seamless. The spice was spicy, and the slow burn was gooooood.
I’m still crying, and I finished the book 20 minutes ago.

[FN · Rating 5 out of 5]

This story is filled with so much heart. Beneath the enemies-to-lovers trope lies a beautifully layered journey that explores both the good and the difficult moments between the characters. When fate brings the FMC, a teacher, to the school where the MMC is the principal in thier childhood neighbourhood, their connection begins to slowly unfold. I loved how the author built their relationship with cutesy gesture and adorable banter, even with all the tension and unresolved feelings between them.

As the story progresses, their dynamic deepens in a way that feels genuine and earned. I also love that the author doesnt only focus on their issues, another character also has an issue, reminding us that everyone carries their own struggles - different stories, similar emotions. The story delivers a satisfying HEA, which left me smiling at the end.

Thank you for the ARC opportunity.

[Bernadett Plaschil · Rating 5 out of 5]

⭐️⭐️⭐️⭐️⭐️

This book grabs you from page one and does not let go.

The pacing is sharp, the energy stays high and every chapter actually matters. It balances spice, heart and character growth effortlessly - I was fully immersed from the start.

The FMC is layered and relatable, even if at times a little too stuck in her past for my taste. Still, her bravery, resilience and the way she stood up for herself made her growth feel earned and super satisfying.

And the Sawyer, our MMC? Pure green-flag perfection. Protective, emotionally present and proof that I will forever love men written by women. He absolutely 💯 stole the show.

Loved the banter and the chemistry, it felt electric, witty, natural. Add small-town coziness, enemies-to-lovers and a snowed-in situation and I was hooked for good. Grab this for a genuinely satisfying read with good spice 😉

[Kat · Rating 5 out of 5]

To start off, I was in a reading slump for the last few weeks, and I wasn’t sure I was ever going to get out of it, but this book dragged me out of it and I ended up staying up until 3 AM and had to force myself to stop to sleep, I wanted to savor it but I NEEDED to know what happened next, I devoured it. It made me giddy, it kept me on my toes.

I love this book so much. Sawyer and Brie were so fun, their problems felt so raw and their dynamic really made it so enjoyable. I laughed so many times, I cried, I swooned. The enemies to lovers was so very well done, the push and pull, the yearning… So so good. I would highly recommend this to anyone who enjoys, enemies to lovers, spice, angst, humor, found family. It was a blast and I CAN’T WAIT for the next book!

***I was provided with an E-ARC from the author, and all opinions are my own.***

[Lawwen · Rating 5 out of 5]

Our FMC Brie returns to the hometown she hates to try to stay afloat while figuring out her future. She can’t get away from her traumatizing past at home or at work, because her boss, Sawyer, was her bully growing up. I went from kicking my feet with their chemistry to wanting to kick teenager Sawyer, then forgiving him in the next chapter. The Principle Problem had my emotions all over the place for these characters. I didn’t think an author could put so many tropes together in a cohesive story, but Sienna Mills did, and did it so well. My only issue is I don’t know how to pronounce Jolly Jalapeño and I want to see Funny Bunny.

I was provided an eARC of this book and this is my honest review.

[Meg O'Hara · Rating 5 out of 5]

I received and read this as an ARC in just 24 hours- if that tells you anything about just how quickly it sucks you in. I really enjoyed the depth of our FMC/MMC as well as the importance of several of our side characters. The Principal Problem underscores the differences in experience, upbringing, trauma, and healing.

To be completely honest- on or about chapter 45 I immediately jumped into the authors DMs to “demand” more Blue Ridge stories, sing my praises for the style of writing, and gush about how I was absolutely losing my productivity (willingly) to live in the world Sienna has created.

Super pleased, a great HEA, and a fabulous introduction to what I believe will be a highly recommendable series.

[Jen Grá · Rating 4 out of 5]

⭐️3.5 stars⭐️
This is a tricky one to rate as I found it to be a super charming, easy read, but on the other hand, I am completely over the premise of boys being mean to girls because they like them. "I gave you childhood trauma, but I loved you all along and look how handsome I am now!" is a harder pill to swallow in 2025 and with daughters of my own. It's a testament to Sienna Mills and how she fleshed out the back story that she didn't completely lose me. 3 stars feels too low as compared to some of the romance books I have read, this is a triumph, but I don't think I'm as quick to forgive the past as the FMC, Brie.
Thanks to NetGalley and the publishers for the advanced copy in exchange for an honest review.

[Emma Clouten · Rating 4 out of 5]

⭐️⭐️⭐️⭐️
🌶️🌶️🌶️


Wow I could not put this book down I loved Brie and Sawyers story line. I loved the character development of both Brie and Sawyer. The spice was absolutely spicing throughout. Sawyer gets bonus points for how protective he got over Brie when it came to his father and brother. I loved how Brie found a safe place in sawyer to open up to him about what happened at her previous school. These two were meant for each other.


I received this book as an ARC in return for my honest review

[Lauryn · Rating 5 out of 5]

Such a good read! Enemies to lovers, forced proximity, small town drama, and a slow burn. It was so good I couldn’t put it down, finished it in 15 hours. The writing makes you feel like you’re there watching it all happen. There are so many details that get brought back up at the end of the book that other authors would forget about. I swear the way that scents are described had me smelling them too. 5/5 would read again!!

[Emily Arriola · Rating 5 out of 5]

I started this book and I did put it down until it was over! I was hooked from the first page! I just loved Brie and Sawyers story and how they evolved from their childhood. It was such a complex situation and I really enjoyed seeing how both characters dealt with their reunion and new roles in each other’s life! Long story short - I really enjoyed The Principal Problem!

❤️childhood “enemies” to lovers
❤️he falls first and hard
❤️teacher x principal
❤️snowed in

[Stacy Bishop · Rating 4 out of 5]

The Principal Problem, by Sienna Mills, is a riveting novel that weaves together a small-town atmosphere, an enemies-to-lovers, and forced proximity, ultimately unfolding into a slow-burn, childhood bully romance. Upon Brie's return home, Sawyer strives to make things right and reveal his true feelings. However, Brie's past experiences with Sawyer, her childhood bully, render it challenging for her to trust him. This book is an excellent choice for the start of the new year.

[Dianna Nguyen · Rating 5 out of 5]

I read this as an ARC reader and finished it in less than a day! I was obsessed with how the story with the MMC and FMC would unravel given their history. I loved Sawyer so much and Brie, as complicated as her past was, I totally found myself relating to her. It’s been a while since I’ve felt so many emotions reading a book. I cried, laughed, got angry, got happy, felt empathy towards her, and just went for a whole ride. I can’t wait for the next book, to be honest.

[Lauren · Rating 5 out of 5]

Very cute, steamy read! I read this book in one sitting.

I often find “romcom” books to be cringey, but did not have a moment of that with this book.

Brie and Sawyer’s interactions for the majority of the book are a classic miscommunication/misjudgment trope, which I love! I also loved the unexpected inclusion of the snowed in trope.

[Megan · Rating 5 out of 5]

I was lucky enough to be part of the arc team 💕this book was amazing, the balance between plot and spice, the depth to the characters, the enemies to lovers, the forced proximity, the confessions and the tension 😮‍💨 this had me laughing and wanting to shake both Brie and Sawyer 😮‍💨 I loved every second of this 🖤

[Ashleigh Kennedy · Rating 4 out of 5]

ARC REVIEW ! ⭐️⭐️⭐️⭐️ + 🌶️🌶️🌶️

Loved this book!
Enemies to lovers
Emotional damage that needs resolving for both characters
Great character development
Just the right amount of romance and spice.
Sawyer and Brie together are an absolute dream team.
Low key feel like a need a book about Nash!
Definitely worth a read!!

[Lacey · Rating 5 out of 5]

Such a great enemies to lovers read! The undercurrents of needing/pinging for the other person are strong with this one! There were some emotional scenes that got me right in the feels. Laughter, crying, angst. All of the things. Can't wait for more in this series!