Akumademo, Imouto ga Hoshiin desu.

Shinya Ninomiya expresses a strong affection for the idea of having sisters but has none in reality. While imagining what his ideal sister would be like, a demon named Ririn appears and offers to grant three wishes. Shinya asks for multiple younger sisters and provides a list of specific traits for them. The next day, his request is fulfilled, and two sisters are now living with him. The story follows the comedic situations that arise from this unexpected development.