Chii-chan Kaihatsu Nikki

Sharp-tongued and morally rigid, Chizuru is a schoolgirl who prides herself on doing the right thing — which makes it especially painful when she gets tangled up in a school embezzlement scandal she had nothing to do with. Suddenly, a creep of a middle-aged teacher named Tamura has leverage over her, and her carefully maintained image is at serious risk. The premise is uncomfortable by design: a young woman trapped in a coercive situation, trying to protect herself while the people who should be protecting her are the ones causing harm. It leans hard into psychological tension and manipulation rather than straightforward action, so if that kind of dark, pressure-cooker drama is your thing, it delivers on that front. The character designs are detailed and the pacing moves quickly across its two OVA episodes. Fair warning though — this is hentai, so explicit content is central, not incidental. If you've watched something like Kuroinu and appreciated the darker narrative framing that comes with that territory, this hits a similar note. It's not going to be for everyone, and it doesn't pretend to be. But if you want a short, intense watch with an actual character setup rather than just pure shock value, Chii-chan Kaihatsu Nikki at least gives you something to follow emotionally before things get complicated for Chizuru.