A groundbreaking drama film titled 'From Yamanashi to Shinjuku by High-Speed Bus...', which usually takes two hours and thirty minutes during the homecoming rush hour, was stuck in traffic for seven hours due to congestion. Seduced by the allure of an unforgettable summer memory, she succumbed to temptation from her neighbor - a married woman. In the confined space of the bus, they repeatedly engaged in infidelity. Even during bathroom breaks, they secretly indulged in sexual acts. Their lust knew no bounds; this was their final spark.