Recently, Aizawa Seiji has been interested in his super cool, sexy and beautiful neighbor, Ugouda Rin, who attends the same university. One day, when he tries to get close to Rin, he’s informed that Rin is gay, and the moment Rin kisses him and tells him “Don't get close to me so carelessly,” Aizawa realizes his feeling towards Rin. Aizawa embraces him passionately and tells Rin “It's okay even if we are just sex friends.” From sex friends to irreplaceable lovers, how will their relationship change...?