Kogasaka Chinami

Likes: Her brother
Dislikes: Temple grinding

Chinami is You's little sister. She tends to be bad at everything (especially in cooking; everything she tries to cook turns into charcoal), except driving her brother crazy. However, she has the ability to become friends with anyone due to her energetic personality and smile.

Spoiler

She is actually his half-sister but they share the same mother. Chinami thinks that her whole life, starting from her birth is just a burden and is also afraid that her dear Onii-chan will leave her just like their mother did. This is the reason for why she wants to take care of You so much.