If a certain demonic stopwatch hits 0, then all hell's gonna break loose - LITERALLY! Genius horology student Akemi Tsunagi correctly deduces that the ancient Hades Watch is guarded by various time puzzles, so she and her eccentric Professor are hired by the Hell Police to solve those puzzles, get to the watch, and destroy it before it's too late! But considering the Hades Watch lets its user turn back time, Akemi has her own plans for when she acquires the cursed timepiece… That is, unless those mind bending time puzzles outsmart her first!