Based on the Light Novels.
Kadokawa has announced on the event “Dengeki Bunko Aki no Saiten 2016" that an Anime adaptation of Tenshi no 3P! (Here comes the 3 Angels!) is in production which will come in 2017.
Anime News Network describes the story as follows:
“The “loli pop comedy” light novel series follows Kyō Mekui, a high school student who tends to skip school due to a trauma in his past. Kyō secretly creates songs using vocal song synthesis software as his hobby. Three girls who just entered fifth grade — the crybaby Jun “Jun-tan” Gotō, the strong-willed Nozomi “Zomi” Momijidani, and the somewhat sleepy Sora “Kū” Kaneshiro who takes life at her own pace — email Kyō. These three girls, who were raised together like sisters since childhood, want Kyō to help them break into music in this “loli & pop symphony” story.”
Via: Anime News Network