What if Conan never turned back into Shinichi, never got the antidote, never left that poisoned body behind, what if he just... lived with it. This OVA answers the question the manga won't let itself ask: what does growing up in a child's body actually cost, and what would it mean to accept it instead of chase the cure. Ten years later, Conan and Ai are still solving murders as kids while their friends move into adulthood around them, not as a setback to overcome, but as the life they chose. It's melancholic in a way the series never allows itself to be. The Detective Boys aren't kids he's protecting anymore; they're his generation, aging in real time while he stays trapped. That gap is the real mystery here.

A decade has passed in this speculative Case Closed OVA, which imagines one possible future for its young detectives. Conan and Ai decide against taking the antidote to APTX 4869 and instead live out their childhoods a second time, growing up side by side with their friends Genta, Mitsuhiko and Ayumi. Ten years on, the group still carries on its detective work together, in a single episode that mixes mystery, adventure and comedy.