I don't know how to articulate what I expected, but I do know this manga only delivered a small portion of it, hidden beneath a bunch of stuff I didn't particularly like. Since I don't really know how to properly collect my thoughts here, I'm just going to make lists. I like lists; they're easier than proper paragraphs.
The Plot
The main plot is the budding romance between a short (5'4" / 165cm) guy named Yuujirou and his tall (6' / 186cm) friend, Rui. It started when Yuujirou saved young Rui from a storm drain he'd fallen into and bloomed into a childhood crush when Yuujirou mistook the then-tiny Rui - who wore a barrette in his hair - for a girl. Yuujirou thought the crush died once he discovered the truth, but Rui's been stuck to him like glue ever since... and grown considerably taller and more masculine as he aged, despite still having a very soft and somewhat effeminate personality. (You see where this is going. I see where this is going. Nobody is surprised.) Now highschoolers, the duo clearly have feelings for each other, but - to quote a panel from the (translated) manga: "both of them [are] astoundingly oblivious."
The journey from friends to boyfriends to lovers is the plot, though far more time is spent as oblivious idiots than partners and things get very rushed once the inevitable relationship happens. Other than ridiculous conflict spawned from lack of communication, there isn't much substance to the plot other than watching these two fools bumble their way through to finding a relationship. I don't necessarily mind that, but I'm just saying: I'm out of plot to describe, here. It's mostly just about the friendship and relationship journey.
Things I Liked
Grumpy & Sunshine - Rui is a sweet guy who wears his heart on his sleeve and acts a bit immature. Yuujirou is a standoffish and brash guy who has a heart of gold beneath all the bravado and often lashes out because he doesn't know how to handle having strong emotions. Opposites attract and whatnot.
Friends to Lovers - I love this trope. I enjoy the automatic chemistry it comes with and the sweetness often found in these kind of relationships.
Realizing Sexuality - I like exploration of characters coming to the realization that maybe what society led them to think is the default doesn't fit their actual interests.
Acceptance - I love a good, realistic story about the perils of navigating a world full of homophobia (because I relate), but I also sometimes just desperately crave something fluffy and saccharine where the people in the main characters' lives are happy for and accepting of them. This contains the latter, and that's exactly what I was in the mood for at the time, so it worked out well. (This isn't a spoiler; whether they'd be accepted isn't really a concern in the plot.)
Gentle Giant - I am a bit of a sucker for the trope of big (in this case tall) guys who aren't particularly athletic and who are into softer things like fashionable accessories and cooking. Rui fits this trope perfectly and I adored that.
Things I Felt Neutral About
Art Style - While there's plenty of detail in the sexualized panels, most of the art in other portions is rushed and lazy and makes the characters look either far too young or, quite often, like they're only vaguely humanoid. I wasn't expecting a masterpiece and I've come to grudgingly accept the abundance of chibi stuff in manga, though, so I shrugged it off.
The Sex - There were some really strange things like a lowkey sweat fetish and random boners (which, okay, is probably realistic). I also kept waiting for the smut... and then felt very lukewarm about it when it arrived. By then, the characters had been so juvenile in behaviour and art style that there was an edge of tonal dissonance when finally they reached that point. It was kind of steamy, albeit with some cringe-worthy dialogue, and overall not awful. I actually kind of liked that it wasn't the most perfect thing and there were insecurities involved. But also, it just felt so strangely out of place by time it arrived. And nowhere near as steamy as I'd have wanted.
Things I Disliked
Nonsensical Dramatics - I know, I know; it's as much a part of manga as it is a part of soap operas, but I just didn't like how the dramatics were handled here. We get absurdity like Yuujirou slamming his fists against a wall while walking to school with Rui, lamenting the crush he's keeping secret. It's just way too melodramatic and ridiculous, especially when these moments get addressed directly by other characters. Ick.
Fourth Wall Breaking - I only slightly tolerate when Deadpool does this. I don't like fourth wall breaks in general, and they're especially ridiculous here in that the story narration gets addressed as actually spoken aloud and then someone gets scolded for breaking the fourth wall. I am very much not a fan of this.
Repetitive Plot Beats - They are clearly in love and jealous of each other's potential other partners and desperate to be together. They are both clearly lusting after one another. There are clear self-esteem issues and communication issues. And these things just keep coming up over and over and over and... It isn't fresh and gets annoying quickly.
Silliness - I don't know how to articulate this, but the best way I can figure is to say that the whole "Rui fell in a storm gutter" thing is a recurring trope and treated as something constantly flashed back to as well. There's just far too much ridiculousness here. (Paradoxically, I got a few good giggles out of the random animal placements, especially when their pets have a "are you kidding us?!" moment over their obliviousness of the mutual crush.) I like a little fluff and a little silliness, but it was amped to eleven in this and I needed it to be toned down a lot for me to truly enjoy the story.
Overall Opinion
Yuujirou and Rui make for a cute couple, but the journey to get there was too littered in things I can't stand. I wanted more spice, but when I got it I was underwhelmed and conflicted by the rest of the manga's tone. This one didn't work for me, and I'm aware some of my gripes are probably unfair due to how common the tropes are, but hey this is about my personal reading experience and for me this just wasn't particularly enjoyable.