Hanaibara

Hassaku’s grandfather loved and collected beautiful things. After his grandfather passed away, wandering painter Hassaku inherited his grandfather’s house. The house is supposed to be empty, but instead it is inhabited by two beautiful siblings, Soyogo, an erotic novelist, and his younger sister, who is his model. Until his grandfather's funeral service is over, Hassaku will have to live with the eccentric pair...

Note: The main story has been completely scanlated, but the last 2 chapters - unrelated oneshots - have not.