In Summer Color, you grew up in a quiet countryside community. Keita is the main character, and Ryoka is a beautiful girl he falls in love with. You're invited to stay in her home along with her older sister Saki. You don't stay with either of them because you're in love with Ryoka. Everything is about to change, and somehow you find yourself right in the middle of a cuckolding adventure. It's not what you expected from this girl who seemed so sweet and innocent.