Shota-kun's father invites his secretary, Kanon Yaotome, over, causing Shota's fantasy world to expand even further. Kanon, blessed with massive breasts, has a gentle yet slightly clingy personality, allowing Shota to take advantage of his position as her boss's son and play increasingly bold pranks on her. He becomes obsessed with fulfilling his desires—touching and sucking her breasts without restraint. Gradually, Kanon finds herself drawn into his mischief, and their relationship grows deeper. Finally, in the real world, Shota's penis enters Kanon's vagina... That single moment changes everything between them.