the way they switched hat tassels from childhood to adulthood. the way that even in their initial designs their hat tassels reflect each other's hair. GRRRRR I HATE COMPLEMENTARY DESIGNS GRRRRRRRRR I FEEL ANGRY
emotional anguish aside. this worldbuilding is so so so cool even if it wasn't used for the official story
i love that one of this manga's main themes is how adults should treat/interact with/take care of children, and how to be good figures in their lives, and the responsibility that comes when interacting with children. it's great stuff and i like what the story has to say about it