A Japanese girl (Kato Youki) is on a three month visit in Taiwan after breaking up with her boyfriend to study Chinese at a language center. One day she has a brief affair with Wu and later he requests her to sign a contract to be his girlfriend for 90 days and she agrees. One of the condition of the contract is they must get separated after 90 days. However, after getting know each other quite well, both find that the relationship seems to be true love and both are unwilling to break the contract agreement as the dateline approaches. What is the outcome of their love story in the end?