My Wife is a High School Girl

At 17 years old, high school student Asami Onohara carries a secret that would make her classmates' jaws drop: she's already married to her physics teacher. Not dating, not crushing — actually married to Kyosuke Ichimaru, the guy who grades her exams. The catch is that her father found out and slapped one very firm condition on the whole arrangement: nothing physical until after graduation. So now Asami is navigating double homework, keeping their relationship hidden from literally everyone at school, and trying to be a wife while sitting in a classroom desk. It's a genuinely weird setup that plays mostly for laughs, with Asami constantly scheming to get closer to Kyosuke while he tries to maintain some semblance of professional dignity. The comedy comes from the gap between how domestic their home life is and how carefully normal they have to act the moment they walk through the school gate. The romance has a slow-burn tension to it since the rules of their situation keep things at a simmer. If you've watched Da Capo and enjoyed that mix of school-setting romance with a slightly absurd premise underneath, this operates in similar territory. It's lighthearted, occasionally suggestive in the ecchi sense, and runs a tight 13 episodes. Madhouse produced it back in 2005, so visually it's of its era, but the core dynamic — two people who are technically a married couple acting like strangers at work — is what keeps it entertaining.