One day, daycare teacher Misa happens to come face to face with Kato, the father of one of the boys in her class. This Kato is the same man Misa met at her part-time job during junior college - the married man she once had an affair with. She thought their relationship was a thing of the past, but after seeing him again something inside of Misa starts crumbling, leaving her heart in a shambles... One night, finding Kato's number still saved in her phone, Misa gives in and calls him...! Added to the mix are Kato's wife Yuka and her lover, Tomoya. All of them old enough to know better but too wretched to care, these sorry souls sink further into the tangled mess of their own murky desires, their struggles laid bare on the pages of this frank tale.