The plot of the anime series "Hozuki's Coolheadedness" takes place in the Japanese underworld. This sector of hell is ruled by the hapless underground king, Emma, who struggles to keep up with counting new souls and assigning them appropriate punishments. The situation worsens when a bloody war breaks out on Earth, sending thousands of new sinners of all kinds to the underworld. Fortunately, Emma has an advisor - the demon Hozuki, who is much more knowledgeable about state affairs than his boss.