第 4 集: 畢業後，Keita 收到父母贈送的溫泉旅館門票，與眾女孩一同前往度假。

4

The sibling's parents give Keita tickets to a hot spring resort as a graduation gift and suggest that he take the girls along on the trip. The siblings go to the hot spring resort, end up visiting an erotic museum, and find themselves in some compromising situations involving Ako's unintentional purchase of alcohol. (Source: Wikipedia)