Based on a novel by Kurumi Inui, “Initiation Love,” is a mystery romance comedy with a stunning and unexpected plot twist. Set in late 1980s Japan, the story, like an audio cassette tape, is divided into two sides. Side–A, is set in Shizuoka City, and focuses on the developing romance between Suzuki (Shota Matsuda), whose nickname is “Takkun,” and Mayuko (Atsuko Maeda), a beautiful dental assistant. Throughout their relationship, Takkun endeavored to make himself more attractive to Mayuko and dramatically altered his appearance. Side–B is set in Tokyo. Takkun relocates to Tokyo for his job while Mayuko stays in Shizuoka. The two engage in a long-distance relationship. The relationship deteriorates as Takkun begins to spend time with co–worker Miyako (Fumino Kimura). Who will Takkun choose to be with?

バブル真っただ中の、1980年代後半の静岡。友人から合コンに誘われ、乗り気ではなかったが参加することにした大学生の鈴木（松田翔太）は、そこで歯科助手として働くマユ（前田敦子）と出会う。華やかな彼女にふさわしい男になろうと、髪型や服装に気を使って鈴木は自分を磨く。二人で過ごす毎日を送ってきた鈴木だったが、就職して東京本社への転勤が決まってしまう。週末に東京と静岡を往復する遠距離恋愛を続けるが、同じ職場の美弥子（木村文乃）と出会い、心がぐらつくようになる。