One Monday morning, Ai notices that Salaryman has a toothache and advises him to go to the dentist.

One Monday morning, an office worker attends his junior high school reunion and meets a woman whom he missed his 'chance' with back in their student days.

One Monday morning, Salaryman asked what Ai did during the Christmas day, which she initially refuses to answer. Later, she revealed that she 'has taken a step into adulthood', becoming from 'I-chan' to 'J-chan'.