Shimamura is a high school student who met Adachi by chance when she was skipping class in the gym. (In the manga versions, she's actually the one who walked in on Adachi, not the other way around.) They hit it off immediately and have been hanging out constantly ever since.
She's got a pretty laid-back personality—the kind of person who can sleep anywhere, anytime, for as long as she wants. Unlike Adachi, Shimamura's got a solid relationship with her family, which makes her naturally more sociable and comfortable around people, even if she doesn't see herself as particularly kind. There's a maternal or big-sister vibe to how she thinks about Adachi, and she definitely enjoys messing with her about it. It's a big part of their dynamic.
Content compiled by AnimeList.moe from publicly available sources.
