Akugyaku Taisen: Jigoku no Ooi Sandatsusha wa Tsumibito to Odoru

Ouka Sakura is cast into the lowest level of hell, prompting Nishijima Shun to leave Earth and return to the underworld to rescue her. He seeks help from Nero, the seventh child of the King of Hell and the princess of laziness, who informs him that only the King can revoke a soul's sentence in that place. Determined, Shun is willing to do whatever it takes to save her, even if it means claiming the throne himself. Using legendary fishermen as his allies, he engages in a battle to determine the next ruler of Hell.