Karin is a *********** girl interested in kissing.

One night, while riding the train, she discovers a man *****ing in the seat opposite her.

The car is empty...

Out of curiosity, Karin kisses the man.

From then on, she continues to kiss the man she is having sex with every night.

As they do this repeatedly, the man wakes up in the middle of the kiss, creating an awkward atmosphere...

The two gaze at each other, and when their lips meet again, the kiss continues unstoppably.

They end up having intimate sexual intercourse alone in the empty car.

Having passed their nearest station, the two get off at an unfamiliar station and go to a hotel, where they kiss and desire each other's bodies until the morning.