A certain large mansion in the countryside. During Obon, all relatives return home at once, making it very lively. Coincidentally, this summer is the year of the 'family groom search.' This time, amateur men recruited by ZUKOBAKO will be drawn into the 'summer vacation' of these colorful relatives. They'll enter hot springs together, have their penises sketched during free research, and have their penises thoroughly inspected before satisfying the family's sexual desires in a massive orgy. The miraculous summer vacation begins.
