Makoto and Yura celebrate their wedding day, but the festivities are marked by the provocative teasing of Yura's sister, Rika. On their wedding night, the couple discovers that they are both inexperienced virgins, leading to a clumsy and premature first sexual encounter. Despite the awkward start, they embrace their new life together as they begin to navigate the challenges of their physical relationship.
As newlyweds struggling with their lack of sexual experience, Makoto and Yura seek ways to improve their intimacy. Their progress is interrupted by the arrival of Miyuki, a former student of Makoto's who harbors an obsessive fixation on him. Through a series of awkward encounters and emotional honesty, Makoto helps Miyuki find perspective on love while strengthening his own bond with Yura.
Makoto and Yura win a getaway to Hokkaido along with their neighbors and Makoto's provocative cousin, Kyoko. During their stay in Niseko, a visit to a unisex open-air bath with another couple sparks an unexpected surge of passion. The trip culminates in a daring night of partner swapping, forcing Makoto and Yura to confront their stagnant sex life and rediscover their intimacy.
Yura decides to take a part-time job as a waitress, sparking intense jealousy in Makoto, who fears her beauty will attract other men. Through a conversation with Kyoko, Makoto learns to overcome his insecurities and trust his wife. Though they reconcile, Yura eventually chooses to leave the job to focus on creating a peaceful home for Makoto, reaffirming their love for one another.