After Ryou's father remarries, he's not sure what to do with three new brothers and a stepmother at the age of 19. As he comes to appreciate his happy new home and family the glue holding them together starts to come undone. How will these four brothers weather tragedy after tragedy and stay together?

Satou Hiroshi is the kind of polite, innocent, cute boy who's popular with guys and girls alike. But word-of-mouth has it that anyone who dates him will be plagued by a series of unfortunate events and near-death experiences - eventually being forced to institute a break-up 'under pain of death'... Will bespectacled, 'uncool', baseball-crazy Tsumabuki Kasumi prove these rumours wrong or experience them first-hand? But after falling for Hiroshi's cute smile upon their (rather weird) first meeting, he's determined to tempt fate and find out whether he can finally break out of this unlucky streak and strike it lucky in his love life!