Kotoko Aihara (Reina Asaki) has struggled since high school to win the affection of Naoki Irie (Kanta Sato), who remains distant despite her unwavering devotion (and his own mother's meddling). When Naoki’s father falls ill, he sets aside his dreams of becoming a doctor to temporarily take charge of the family business, including agreeing to an arranged marriage with the heir of a business partner to secure the company’s future. Heartbroken, Kotoko agrees to go out with Kinnosuke (Shimon Okura), her loyal admirer since high school, even though her feelings for Naoki linger – and Kinnosuke even surprises her with a proposal. Will Kotoko finally let go of Naoki, or is there one more twist in store? This is the final installment of the "Mischievous Kiss the Movie" trilogy based on Kaoru Tada’s 1990s manga series "Itazura Na Kiss."