Rin Todoroki's life's pursuit of completing his parent's unfinished novel has left him pushing thirty without a penny to spare. Desperate for a roof over his head, he takes up a generous offer of rent-free housing in a shared development known as 4x4 Riverside, but the landlord Sei has some ulterior motives – he's a notorious philanderer and Rin is just his type. Now he needs a real job if he doesn't want to end up as Sei's gigolo! Luckily, he's got a bunch of well-connected new roommates to help him out, but sex is all he's really good at, so he decides to butter them up by getting into bed with them... and winning their hearts in the process.