The protagonist, Yuuji, is a ronin studying hard to get into college. His parents sell his childhood home and move abroad, throwing him out of the house. His recently married older brother, Yuuichi, offers him a room. Yuuji feels awkward intruding on his brother's newlywed life, but takes Yuuichi up on the offer.

Yuuji walks into a new life of bewilderment, though, as he suddenly starts having sexy encounters with his new sister-in-law and the seductive housewife next-door.