What do you think?
Rate this book
Castle Swimmer #2
Castle Swimmer: Volume 2
Two mermen reject their destinies and embark on a raucous adventure as big and unpredictable as the ocean itself—and a romance that nobody could have predicted—in the stunning second installment of the hit Webtoon series Castle Swimmer.
The sharks want Kappa dead, and time is running out for Prince Siren to save him. Queen Susca knows Siren doesn’t have the courage to kill Kappa, and for the sake of the kingdom, she’s willing to do the deed herself. As tensions run high, neighboring queens pay the sharks a visit to offer an alliance, and while they might just be the means of escape the two mermen have been looking for, it’s unclear if they can be trusted.
Siren will do anything to get Kappa to safety—even if it means never seeing him again, and even if all Kappa wants is to stay by his side. Yet escaping the queen’s spear will take all of Siren and Kappa’s courage and cunning, and there’s no guarantee they’ll both make it out alive.
This beautiful graphic novel collects episodes 20-41 of Webtoon’s Castle Swimmer and includes a never-before-seen bonus chapter featuring Kappa and Siren.
The sharks want Kappa dead, and time is running out for Prince Siren to save him. Queen Susca knows Siren doesn’t have the courage to kill Kappa, and for the sake of the kingdom, she’s willing to do the deed herself. As tensions run high, neighboring queens pay the sharks a visit to offer an alliance, and while they might just be the means of escape the two mermen have been looking for, it’s unclear if they can be trusted.
Siren will do anything to get Kappa to safety—even if it means never seeing him again, and even if all Kappa wants is to stay by his side. Yet escaping the queen’s spear will take all of Siren and Kappa’s courage and cunning, and there’s no guarantee they’ll both make it out alive.
This beautiful graphic novel collects episodes 20-41 of Webtoon’s Castle Swimmer and includes a never-before-seen bonus chapter featuring Kappa and Siren.
304 pages, Paperback
Published June 3, 2025
23 people are currently reading
2794 people want to read
Ratings & Reviews
Friends & Following
Create a free account to discover what your friends think of this book!
Community Reviews
Displaying 1 - 30 of 146 reviews
September 25, 2025
Eeeeeeeeeep. They are kissing kissing kissing … this so freaking cute, but first there is drama and bloodshed. Loving it 😍
September 8, 2025
reread 🦈🤎
January 8, 2025
Super excited to get the physical copy of one of my favorite webtoons :)
January 3, 2025
⭐️ 4 stars ⭐️
This comic just keeps getting cuter and cuter. I need these adorable boys to get their HEA.
I received a free copy of this book from NetGalley, and am leaving this honest review voluntarily.
“Despite everything that happened, the time spent with you is the happiest I’ve ever been”
This comic just keeps getting cuter and cuter. I need these adorable boys to get their HEA.
When we meet again,
Let’s change are fate together.
I received a free copy of this book from NetGalley, and am leaving this honest review voluntarily.
December 19, 2025
how do I tell my mom that i'm not giggling and kicking my feet cause i'm texting a guy but instead bc two gay fish boys just kissed 😭 I LOVE THEM SO MUCH THIS SERIES IS SO GOOD!
September 30, 2025
read quite a while ago but forgot to mark it here. I'm excited to be able to buy volume 3 next year, though!
January 8, 2025
“when we meet again, let’s change our fate together.”
kappa and siren are back and more adorable than ever. the second volume of castle swimmer picks up where the first left off, with siren searching for a way to save kappa, and covers the second half of their time in the castle as their relationship evolves and they learn about a twist in the prophecy that brought them together.
i just love this series. it’s the perfect escapist read—sweet and heartfelt and beautifully illustrated—and i’m always left wanting more. kappa and siren inspire each other to want more out of life than their preordained destinies, and i’m looking forward to their adventures outside the castle in (i hope!) the next volume.
thank you to netgalley, wendy martin, and ten speed graphic for the eARC!
rating: 4.0/5.0 stars
July 3, 2025
I love these merboys so much~
May 19, 2025
Oh, I love this series. Like I said in my first review, this has the perfect balance of cuteness and suspense. It's a super funny and adorable read, but there's also a well-developed plot, so it's definitely not just vibes. I hope I'll manage to continue this on Webtoon, because I absolutely adore this.
February 8, 2025
Very cute and I'm excited to see how this one progresses. I don't have the bandwidth to stay up to date with webtoons so I love when they get published as graphic novels. I love all the sea images and different fish inspo the characters are created from. This one is a bit cuter than the first if only because we get a little bit more progression, which is to be expected as a story continues. I can't wait to read more.
December 31, 2025
I laughed, cried, gasped, and giggled reading Siren and Kappa’s story. This is the cutest graphic novel, with the most loveable characters. I haven’t enjoyed a graphic novel as much as I did this one in a long while. The plot is well-paced, and keeps the reader interested (+ in suspense). I didn’t expect the twist at all!
Looking forward to volume 3!!! 🧜♂️🌟🦈
4.5 💗
Looking forward to volume 3!!! 🧜♂️🌟🦈
4.5 💗
August 20, 2025
AAAAH ik vind deze serie ZO LEUK!! En dit deel was ZO CUTE, maar ook erg grappig en spannend. Dit was gewoon top.
June 2, 2025
Picking up where the first volume left off, Castle Swimmer continues the story of Prince Siren and Kappa. They may be destined to be enemies, but find themselves falling deeper into the trenches of love. As Prince Siren continues to plan a way out for Kappa, he hits many roadblocks along the way. Both no longer care for any preordained destiny; they will make their own future, and not through any harm toward each other.
Creative, sweet, and charming, Castle Swimmer remains a family-friendly love story about two boys who are both looking for where they belong. I read this in one sitting, and it was a delight to dive back into this world and watch Siren and Kappa not only connect with each other, but become more fully realized in their individual identities. Values are cemented and fought for, and lessons are learned. There is more to come, and I’ll be happy when it does!
Creative, sweet, and charming, Castle Swimmer remains a family-friendly love story about two boys who are both looking for where they belong. I read this in one sitting, and it was a delight to dive back into this world and watch Siren and Kappa not only connect with each other, but become more fully realized in their individual identities. Values are cemented and fought for, and lessons are learned. There is more to come, and I’ll be happy when it does!
February 6, 2025
I've been following Castle Swimmer since the very beginning, and it’s so exciting to see it in book form. This second volume continues the beautiful journey of Kappa and Siren, and I’m so invested in their story.
The adaptation from webcomic to print was done perfectly, keeping the charm and flow of the original. The worldbuilding is stunning, with so much depth and beauty, and there’s still plenty left to explore. The humor is fantastic, too—it’s silly in the best way, bringing levity to the more emotional moments.
And knowing what’s coming next? Trust me, it only gets better. If you haven’t started this series yet, now is the perfect time.
Thank you NetGalley for the arc! It was a delight!
The adaptation from webcomic to print was done perfectly, keeping the charm and flow of the original. The worldbuilding is stunning, with so much depth and beauty, and there’s still plenty left to explore. The humor is fantastic, too—it’s silly in the best way, bringing levity to the more emotional moments.
And knowing what’s coming next? Trust me, it only gets better. If you haven’t started this series yet, now is the perfect time.
Thank you NetGalley for the arc! It was a delight!
January 8, 2025
We got a smooch!!!! It feels like the slowest of slow burns, but it only took 2 volumes and a life or death situation. Now I wait patiently for the next one while they angst-fully wish to be back in each other’s arms.
This was just as sweet as the first book, but a lot happened in those 300 pages. Not only did we… NOT fulfill the prophecy, we found out that it had been different than originally led to believe. 🤯🤯🤯
Going into volume 3, the vibe is that we definitely need them to find a solution to that curse so that no one has to die!!! PLEASE!
This was just as sweet as the first book, but a lot happened in those 300 pages. Not only did we… NOT fulfill the prophecy, we found out that it had been different than originally led to believe. 🤯🤯🤯
Going into volume 3, the vibe is that we definitely need them to find a solution to that curse so that no one has to die!!! PLEASE!
January 2, 2025
4.5/5
Didn't realize this webtoon was being published physically and I've restarted my re-read on webtoon to catch up to the current episodes and I'll most certainly be getting the physical releases as they come out now. This physical copy covers episodes 20-41 and the webtoon (as I'm currently marking this is sitting at Episode 169 - Season 3 finale). So, even though I've read quite a bit further than the physical publications, it's what Goodreads currently has.
Didn't realize this webtoon was being published physically and I've restarted my re-read on webtoon to catch up to the current episodes and I'll most certainly be getting the physical releases as they come out now. This physical copy covers episodes 20-41 and the webtoon (as I'm currently marking this is sitting at Episode 169 - Season 3 finale). So, even though I've read quite a bit further than the physical publications, it's what Goodreads currently has.
January 30, 2025
If you’re a fan of the cute and sweet vibes of Heartstopper I think that you’ll have a fun time with this series. I enjoyed volume one more and I can’t quite put my finger on why. I think it might be because cuteness of the art style makes the stakes not feel as high. I would still recommend checking this series out though and I’m excited to see what happens next.
Thanks to the publisher for providing me with a free e-ARC in exchange for my honest review.
Thanks to the publisher for providing me with a free e-ARC in exchange for my honest review.
January 14, 2025
Thank you to NetGalley and the publisher for the ARC in exchange for an honest review!
the aquatic adventures of prince siren and beacon kappa continues!! this second installment brings more cuteness and surprises for readers that will make you wanting the next volume! this one especially also made me giggle so much hehe siren and kappa are such cutie pies
the aquatic adventures of prince siren and beacon kappa continues!! this second installment brings more cuteness and surprises for readers that will make you wanting the next volume! this one especially also made me giggle so much hehe siren and kappa are such cutie pies
January 31, 2025
Such a sweet yet deep story. The Plot follows a merman who's job is to make the dreams of underwater creatures come true but it comes at a high cost to him. The soft and tender romance between the main characters is done really well and realistically and is the main highlight for me. (Received a review copy from Netgalley)
February 21, 2025
no se pq me da verguenza leer webtoon pero bno, esta bien bueno la verdad
February 26, 2025
Dragged on a little but still cute
Read
July 5, 2025I very much enjoyed this installment of this engaging and cute graphic novel series. I especially love all the side characters and the touches of humor. This is a series I will definitely be continuing on with as it releases. If your brain has had a hard time reading lately (my attention span is like 10 seconds at this point) this is a perfect book to enjoy in just a couple of sittings. Highly recommend!
ARC provided by NetGalley
ARC provided by NetGalley
July 27, 2025
I really liked this story and the plot twist. I’m definitely still curious how the prophecy is going to play out. Eagerly waiting for book 3!
As always, the art is just beautiful.
Favorite character: Queen Nee.
Favorite parts below:
Siren’s mom: My son wouldn’t be interested in a PRINCESS.
Queen Nee: We have PRINCES too! Many sexy princes. It’s a large family. Ah, yes! My three beautiful sons! Pr…once, Pring, and …Princely!
Siren: You’re amazing, Kappa.
Kappa: Nah, I’m just the BEACON. Seducing giant jellyfish comes with the job.
As always, the art is just beautiful.
Favorite character: Queen Nee.
Favorite parts below:
Siren’s mom: My son wouldn’t be interested in a PRINCESS.
Queen Nee: We have PRINCES too! Many sexy princes. It’s a large family. Ah, yes! My three beautiful sons! Pr…once, Pring, and …Princely!
Siren: You’re amazing, Kappa.
Kappa: Nah, I’m just the BEACON. Seducing giant jellyfish comes with the job.
July 26, 2025
I am loving this sooo much
August 30, 2025
I am going to cry because they're so damn cute. BUT UGHHH, HIS MOM WAS SO SELFISH. For good reasons, but...
September 20, 2025
UTTERLY INDESCIBABLE. I loved it just as much as the first part! I don’t want to wait for the next volume though!!!
October 7, 2025
20/10 no notes.
I hereby declare this book illegal.
Literally tried to kill me with cuteness.
Actually can’t handle it.
I hereby declare this book illegal.
Literally tried to kill me with cuteness.
Actually can’t handle it.
December 1, 2025
2.5 stars
There's nothing wrong with this, and I can see how people can love this series but god did I find it so boring and it was such a slog to get through. I don't think I'll be continuing it just because of that.
There's nothing wrong with this, and I can see how people can love this series but god did I find it so boring and it was such a slog to get through. I don't think I'll be continuing it just because of that.
May 9, 2025
*An ARC was provided by NetGalley and the publisher in exchange for an honest review*
Did you grow up with some weird fascination with sirens, mermaids, fish, or any of the above? Fairytales and folklore been your shtick since the release of Shrek? Chosen one destinies get your blood pumping?
Boy oh boy, have I got the series for you.
As I shared in my review of Castle Swimmer, Vol. 1, Kappa and Siren have been my sweet little fish boys since freshman year of college. I remember finally giving in to the Webtoon hype, curling up under a blanket, and coming out of a Castle Swimmer-induced coma a few hours later and being livid because I was fully caught up and deeply invested.
Not much has changed. I still love my precious little fish boys and their story of destiny, royal duty, and young love. I laughed at how silly these two were and fist pumped every time they got a helpful hint for how to thwart the "kill the beacon to save the people" narrative. I always forget how much I love Queen Nee and her shameless antics.
The perfect story to sink into for an afternoon of fun antics and lovable characters.
Did you grow up with some weird fascination with sirens, mermaids, fish, or any of the above? Fairytales and folklore been your shtick since the release of Shrek? Chosen one destinies get your blood pumping?
Boy oh boy, have I got the series for you.
As I shared in my review of Castle Swimmer, Vol. 1, Kappa and Siren have been my sweet little fish boys since freshman year of college. I remember finally giving in to the Webtoon hype, curling up under a blanket, and coming out of a Castle Swimmer-induced coma a few hours later and being livid because I was fully caught up and deeply invested.
Not much has changed. I still love my precious little fish boys and their story of destiny, royal duty, and young love. I laughed at how silly these two were and fist pumped every time they got a helpful hint for how to thwart the "kill the beacon to save the people" narrative. I always forget how much I love Queen Nee and her shameless antics.
The perfect story to sink into for an afternoon of fun antics and lovable characters.
June 3, 2025
Thank you to NetGalley and the publisher for giving me an ARC of this book in exchange for an honest review!
This is just such a cute webtoon! I love it so much!
The art style is beautiful. It is easy to read and get into.
I was laughing out loud at so many parts. The author has a great sense of humor!
I love Siren and Kappa together and separately as their own characters.
Skiff is so adorable as well! I loved how he helped Siren and continues to be a good person.
The queen’s Krilli and Nee were such a great addition to the cast of characters. I would love to see more of them! They had me laughing at all of their scenes.
I never really got upset with Siren’s mom, even though people have a right to be. I understand the love she has for Siren. Seklie is hilarious though, her character always makes me laugh as well.
It had a little bit of a twist that I wasn’t expecting, which was cool for a mostly lighthearted webtoon.
I cannot wait to read more of this when the next volume comes out!
This is just such a cute webtoon! I love it so much!
The art style is beautiful. It is easy to read and get into.
I was laughing out loud at so many parts. The author has a great sense of humor!
I love Siren and Kappa together and separately as their own characters.
Skiff is so adorable as well! I loved how he helped Siren and continues to be a good person.
The queen’s Krilli and Nee were such a great addition to the cast of characters. I would love to see more of them! They had me laughing at all of their scenes.
I never really got upset with Siren’s mom, even though people have a right to be. I understand the love she has for Siren. Seklie is hilarious though, her character always makes me laugh as well.
It had a little bit of a twist that I wasn’t expecting, which was cool for a mostly lighthearted webtoon.
I cannot wait to read more of this when the next volume comes out!
Displaying 1 - 30 of 146 reviews