When talking about fan service I think we all understand it as just that fan+service something the fans want to see. Usually this involves the characters looking more provocative but sometimes what the fans want to see is a What If narrative that lets fans enjoy for example their favorite characters ending up together. I feel like this kind of fan service is different and personally I had never looked for it or thought I wanted it until I saw this OVA. Now i would totally buy a overpriced blue ray if that meant I’d get to see a full season of Kurumi x Shidou episodes even if it had no relevance to the main plot whatsoever.
10/10 fan service. Would recommend. Will watch again.
