Yuri, who has been married for five years, is surprisingly active despite her appearance. Recently, she's really into running and even participates in marathons. One day, while running as usual, she carelessly falls and gets injured. But it was the man who would become her lover who helped her out there. Perhaps because she was usually treated like a maid by her husband, his gentlemanly and kind treatment made her heart waver, and she ended up crossing the line. Once the wandering heart starts moving, it doesn't stop and runs wild. This time, such a couple decided to go on a trip.
