Gakuen Utopia: Manabi Straight! - Kirakira Happy Festa!

Originally a console visual novel, and as such non-adult by default, this game focuses on a slice-of-life story of Manami Amamiya. The year is 2035 and the Earth is suffering from decreased birthrate. Also, many schools are closing because they lack sufficient number of students. Seiou Academy (聖桜学園) is one such school in crisis of being closed. Manami Amamiya, who switched schools and recently became the student of Seiou Academy, is trying to prevent that from happening. Along with her friends, she is on a mission to bring back the vitality in the area, help various townsfolk, and organize the summer festival.

The game is based on the Gakuen Utopia: Manabi Straight! manga from 2005 which also spanned anime series which started airing in 2007, just a couple of months before this game's release.