Satoshi, a part-time worker who's practically living with his girlfriend, is constantly arguing with her because he doesn't understand women's feelings. He confides in Alice, a senior colleague at his part-time job, about his love life. Alice overhears the conversation, seduces Satoshi, gets him drunk, and they have sex. From then on, the two of them repeatedly engage in sexual activities during their part-time jobs. However, Satoshi feels guilty towards his girlfriend...