Back when architect Motoharu Maki was just starting out, he nursed a one-sided crush on another—his former mentor Mibu. His current love, Kouta, is shocked to find out that, unlike Motoharu’s usual type, Mibu is sophisticated and austere. And even though Kouta trusts Motoharu and believes he will be faithful, he can’t help but feel a little shaken. What else doesn’t he know about Motoharu, and should he be worried now that Mibu is back in Motoharu’s life?