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.