The Sagemiya family is cursed in that its members are sexually aroused in the presence of another of the same bloodline. Sagemiya Misaki and her elder twin, Shun, are both disgusted over this and have sworn to resist the calling of their blood. However, Shun loses his composure and goes to their elder sister, Kagu, for release. After Misaki finds out, she too loses her resolve and seeks out Shun.

Far away from the hustle and bustle of the city lies a small rural town in a mountainous region. A young man meets a pair of beautiful sisters there along with their mother, and lives together with them. Their days together are full of happiness, but he didn’t know that there is a hidden secret.

Based on the game by Lune TeamBitters. Seiji is a permanent part-timer. He has been dating a girl, Ai, for two years and he is now thinking about marrying her. But one day, he has a traffic accident and breaks his leg. Like this, he is hospitalized… “I’ll visit you every day,” Ai says it with a smile. But their relationship gradually changes after his hospitalization… A real estate broker who hit Seiji. A guy at the same hospital room. A handsome doctor in charge of him. A co-worker at his shop. A nurse who is his ex-girlfriend. Various people cut in on Seiji and Ai’s relationship… Will they be able to overcome it and keep their relationship…?