"Oppai Momitai" tte Sakendara, Imouto no Tomodachi to Tsukiau Koto ni Narimashita.

Synopsis

"I want to fondle boobs!" His prayer was answered by an angelic girl named Miko-chan. "I-if I let you touch my breast, will you go out with me?" It's a sweet story of their daily lovey-dovey life. Isn't it wonderful to have a girlfriend? (Source: Kadokawa, translated)