The good-natured and clumsy Mizumura Umi can't seem to do anything right. Burdened by debt, he eventually gets kicked out of his home one day. Just then, he gets a call from his twin brother, who is on a business trip abroad. "I'll let you stay at my place, and I'll even pay off all your debt. But in return..." When he enters his brother's house, a mysterious man named Yukita Chiaki shows up, hugs him and kisses him. It turns out this man is actually his brother's lover.