The motto of the sharehouse Komarisou is "everyone is like family".

Students Mamoru and Yuuto are current lodgers.
The landlady is Sadako, who very generously discounts the rent.
Among the other lodgers is a girl named Chise.

Chise and Mamoru have gotten close since Mamoru's
defeat in the arena of forbidden love with married woman Akina.

Chise grows more fond of Mamoru.
A shadow of impropriety is lurking overhead............

[From DLsite English]