Love is the Number of Keys

Jun Amanuma moves into an apartment complex as assistant manager when his dad heads overseas for work — his first real taste of living on his own. Sounds pretty normal, right? Except the building he's now responsible for turns out to be a sex service establishment, and nobody thought to mention that in the job description. That's the setup, and the OVA leans fully into the chaos of Jun figuring out exactly what he's signed up for while getting to know the residents, particularly Miki Aihara and Sumire Oosawa, who make his new situation considerably more complicated. The tone is light and plays the whole thing as an erotic comedy of errors — less serious drama, more 'this guy cannot catch a break.' If you've watched Resort Boin and enjoyed that mix of surprise and character-driven comedy in the hentai space, this hits a similar note. It's also in the same neighborhood as Shusaku in terms of a protagonist dropped into an unexpected adult environment and having to navigate it. At just one episode from Concept Films, it's a quick watch that doesn't overstay its welcome — it sets up its premise, delivers on the genre expectations, and keeps things moving. Nothing groundbreaking, but if you're looking for something in this genre with an actual setup rather than zero context, this one at least gives you a reason to care about what's happening.