One day, young housewife Hotaru agrees to babysit Shota, the son of an acquaintance. Shota, a brat with an obsession for big breasts, becomes instantly infatuated with Hotaru's huge tits and starts acting cheeky right away. Ignoring his advances completely, Hotaru pays him no mind, so Shota escalates his pranks further. From breast groping and titty fucking to creampie sex, their encounters grow increasingly intense—and through it all, their relationship takes a deeper, more intimate turn.