Ikusei

The protagonist, in the midst of puberty, is troubled by the immoral desires that burn in his chest. What exactly does he want?

Through contact with his mother, Mitsue, and his childhood friend, Miki, he gradually becomes aware of his true, repressed desires.

The protagonist, Mitsue, and Miki. When the door hidden in each of their hearts opens, the world that was ordinary will be rewritten in lewd colors.

[From official site]