Yeongju has had a "touch of destruction" since he was a child. After even his beloved pet was affected by it, he vowed never to raise anything ever again. But at that very moment, a mysterious man gave him a "Calculus" as a gift. The man claimed that the Calculus would be a being that wouldn't be harmed by Yeongju's hands and would always stay by his side. Yeongju believed his words and named the Calculus "Oki." Before he knew it, just as the man said, Oki grew healthy and became Yeongju's most precious friend...

On Yeongju’s first night living alone after starting university, he woke up to a strange, sensual sensation. Standing before his eyes was a strikingly handsome man! "I've wanted to touch you all along, Yeongju. You have no idea how long I've waited for this moment." This beautiful man fondling Yeongju's body is Oki?! "I love you, Yeongju. Will you bear my child?"