When exhausted workaholic apothecary Colette jumps into a well, instead of dying she finds herself caring for a new patient: Hades, Lord of the Dead. As Colette goes back and forth between her world and the underworld, new patients of every kind arrive daily!

After some tough-love training by the entire Underworld, the otter apprentice Kotsume faces his final test! Can he recover his position as a servant of Poseidon? Later, a near kiss from Lord Hades leaves Colette in confusion!