Boku no Natsuyasumi 3: Kitaguni Hen - Chiisana Boku no Daisōgen

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.

Aside from the graphical improvements, the game closely follows the original design. Boku has a limited number of 31 days where time passes in real-time as soon as he moves to a new screen. The game consists of fixed screen, pre-rendered environments with 3D models and a cinematic camera with a different viewpoint for each scene. The player is free to choose how to spend his time as it is presented as a sandbox environment. Many activities from the previous games return such as catching different types of insects and swimming with a bottle cap system for oxygen, but there are also new activities such as cow milking, feeding a calf, visiting a glass studio, Chinese jumping rope and a grass sledding mini-game. He can also choose to attend Tanabata, a Japanese star festival. At the end of the day a page can be created in a journal.

Many scenes offer interaction for the sake of exploration, with no further purpose. Time advances when a new scene is entered, so it is not possible to complete all content in a single playthrough.