Seeing Tasuku grow and learn throughout this manga is the best thing. There's a lot he doesn't get about people at first and he makes a lot of mistakes like making rude comments or the kabedon but he sincerely reflects and tries to learn from them. He starts to think about how other people are affected by his actions and how they would feel.
Tasuku is interested in Shia san cos he likes her, but he doesn't know anything about her. And he recognises that to her he's still an immature child, which is why he tries his best to learn about Shia san and how to interact with people, even if it means making more mistakes. He's an awkward but straightforward kid. Its pretty established that communication is key to relationships. But that doesn't make it any less difficult. Tasuku's willingness to do something even adults struggle with is incredible. And in doing so, he learns about Shia san and how to treat people.
So having this chapter where Tasuku shows Shia san that he likes her, and he's paid attention and learnt about her as a person, and even after seeing the good with all the bad he STILL likes her, even though she's a pain sometimes and she knows she's a pain and she hates herself for her flaws..that's such a big step not only for their relationship but also his own growth. And you've got all the little details like how he's helping his brother make onigiri, how he misses his shot cos he's thinking about Shia san, how he went to Gusto to look for Shia san and then remembered she likes donuts and went there......and of course the panel of Shia san finally smiling, not after hearing her good points, but her bad ones, because that's the moment she understands Tasuku's "like" isn't just a feeling towards a crush, it's a feeling towards a person that he's taken the effort to understand, flaws and all.
I love them. I love this manga. I'm going to explode.