Arisa Hanyu, a new transfer teacher at Shota's school, is actually the daughter of his mother's close friend—and due to this connection, the two begin living together. Arisa is kind yet mischievous, a busty woman with prominent, alluring breasts. As they share daily life under one roof, their physical attraction grows stronger. Playful pranks and erotic exchanges gradually close the gap between them, turning their cohabitation into the beginning of a new, intimate relationship.