Bakayarou no Kiss

Kujo Minato, Miyama Ririna, Irie Yugo, and Osada Keita were four close friends until Ririna had to transfer to another junior high school. This is the story of Minato, who is now a high school senior, and his 30-day summer adventure with his friends as he finds out that Ririna, who is also his first kiss, appears in a love reality show.
(Source: DramaWiki)