Boku no Natsuyasumi 3 is the third main game in the life simulation series of spending a summer vacation in Japan. This time the fourth grader Boku goes to his uncle and aunt's farm in the wide-open countryside of Hokkaidō on 1st August 1975. It is the same period as the previous two games, so once again it is an alternate universe sequel. He is dropped there by his father as his sister will be born that month. His uncle and aunt have a daughter called Midori who has the same age as Boku.

This time the fourth grader Boku goes to his uncle and aunt's farm in the wide-open countryside of Hokkaidō on 1st August 1975. It is the same period as the previous two games, so once again it is an alternate universe sequel. He is dropped there by his father as his sister will be born that month. His uncle and aunt have a daughter called Midori who has the same age as Boku.