Boku no Natsuyasumi 4[b] is a 2009 adventure video game developed by Millennium Kitchen and published by Sony Computer Entertainment for the PlayStation Portable.

Like Boku no Natsuyasumi 2, it takes place in a Japanese coastal village.

The main character spends his summer vacation in a coastal village in Japan.

The game contains the familiar bug collecting, beetle fighting, swimming, fishing, morning exercises, and family meals from previous series entries, but also features new activities, such as playing a taiko drum, challenging other children to duels with mechanical toys, a beetle circus, and several tabletop games.

[2] Popular Japanese review magazine Famitsu rated the game a 31 out of 40 (8/8/8/7).