A group of friends decided to play a friendly game of swinging, and while three out of four are on board, Rina loves her boyfriend too much to agree. But with a little liquor and a promise of no hurt feelings, the game is set into motion!.

It's been some time since the lover's game has been set in motion, and while the rest are all having fun, Rina is still having some difficulties being with a womanizer like Koudou instead of her boyfriend. Will she continue to fighter her feelings or finally give in and be honest?.

Last Part is A collection of two-page spreads serving as a supplement to the main series, with various standalone scenarios rather than a continuous story.