While Mamiya Jun is active as a gravure idol, her vacation at Nasu Onsen Village takes a thrilling turn. Just like her usual work, she joins a mixed-gender bath wearing an extremely tiny bikini. Her figure constantly draws attention, especially her big tits that attract countless stares. The surprising fact is that her first sexual experience was only three months ago, making one wonder, "Is she a virgin?" However, during sex, she suddenly undergoes a dramatic transformation, screaming loudly as she squirts uncontrollably—an absolutely shocking awakening.