During a trip to a hot springs resort, the tension between Akitsuki and the prickly Airi reaches a breaking point. After a series of provocative encounters fueled by a mysterious aphrodisiac, Airi reveals her deep-seated insecurities and her longing for her father's genuine affection. Following a night of passionate intimacy and mutual confession, Airi wakes up with a blackout, leaving her oblivious to their shared secrets just as Marina arrives.