Studio Ten (known for other dark fantasy/adult titles)
2004 - 2005
While hiding in an old, dusty clock tower (or science lab, depending on the adaptation), he discovers a strange, ornate stopwatch. Upon activating it, a deep voice explains the rules: "When the hands stop, so does the world." -Eng Subbed- Gakuen de Jikan yo Tomare 1 - 2