Adam's Sweet Agony

When a pandemic renders virtually every man on Earth impotent, there is one notable exception: a high school kid named Itsuki. That's the setup, and it goes exactly where you'd expect from there. To keep his condition under wraps, Itsuki transfers to a school that happens to be 90% girls, which is either the worst possible decision or the most inevitable one depending on how you look at it. Once he arrives, he runs into the usual cast of complications: a warm, friendly upperclassman named Akari, a teacher named Kaede who is visibly not handling the global situation well, a tomboyish student called Aki who carries herself like the school's unofficial prince, and Yui, an heiress with her own agenda. The early episodes are mostly Itsuki trying to keep his head down while everyone around him makes that increasingly difficult. It's a harem setup dressed in a light sci-fi premise, which gives it a little more texture than the average school romance of this type. Character designs come from Yoshihiro Watanabe, whose work you might recognize from The Testament of Sister New Devil, so visually it's polished. If you've watched High School DxD or To Love-Ru and wanted something with a slightly more grounded world-building hook underneath the fanservice, this 8-episode ONA scratches a similar itch without overstaying its welcome.