Shounen ga Otona ni Natta Natsu

Ryuuki Kirishima is a teenager living with his older sister after losing both parents, quietly getting through summer with his friends — soccer, hanging out, the usual. Then one afternoon they watch some adult videos as a joke, and Ryuuki finds himself genuinely fixated on one actress in particular, a newcomer named Kiriru. He can't quite explain why. Then she shows up in his life in person, and that summer suddenly gets a lot more complicated. This 4-episode OVA from Blue bread is adapted from a manga and leans into that nostalgic, small-town Japanese summer atmosphere — think long afternoons, cicadas, the feeling that something is shifting but you can't name it yet. Underneath the hentai content, there's a genuine coming-of-age frame here: grief, first attraction, the slow realization that childhood doesn't last. If you've ever watched 5 Centimeters per Second and felt that quiet ache of something ending, or connected with the emotional texture of Anohana, you'll recognize the mood this is going for. It's not as restrained as those titles, obviously, but the emotional bones are similar. Four episodes means it moves quickly without much filler. The character setup is straightforward, but Ryuuki feels grounded rather than generic — a kid carrying loss, stumbling into something he doesn't fully understand yet. If you want something with actual emotional context around its adult content rather than pure fantasy scenarios, this one puts in more effort than most in that space.