By the end of chapter 21, you could literally just end the story there, there is some things that need to be developed such as Tae-shin, but I would not complain if the story just ended right there. Matter of fact, I'll even clap if it ended there. Like just finishing it up with some side stories that include Tae-Shin's development or aftermath and that would be okay. Better not be any unnecessary arcs in S2..
Insanely cute, I like the chibis a lot