Akino is Natsuhito Sewa's younger sister, and they both have 2 younger siblings (a girl and a boy) who are twins. She is a middle schooler.

Usami-san wa Kamawaretai!
Nagisa Usami is a yankee who suffers from a rare disease which causes her health to decline if she feels lonely. Natsuhito Sewa, the boy who sits next to her in class, realizes this and keeps her company, but the only way Usami believes she can cure her illness is to make lots of friends, a process she might find quite difficult due to her aggressive looks and personality.