Shita no Kai no Yokufuman na Mucchimuchi Mama-san kara no Approach ga Sugoi

The protagonist, Ikuto, was on friendly terms with Keiko, a single mother who lived in the same apartment building. One day, while Ikuto was going about his daily masturbation routine in his room, he must have forgotten to close the window—and Keiko, living on the floor below, heard him…! Frustrated by the demands of raising a child and working full-time, Keiko couldn’t take it anymore and went to Ikuto’s room… “If you’d like… maybe I could help you out…?” And so… his first-ever sexual experience began, carried along by the flow of events… Wow…! An older woman’s pussy… felt this good…!! Every move Keiko made—with her wealth of experience—was too intense… Ikuto found himself becoming more and more hooked on Keiko’s body, even though she was more than a decade older than him────

(Source: Melonbooks, translated)

Note: Released at Comiket 108