Koori no Mamono no Monogatari

A demon named Blood, imprisoned in ice for decades, seeks a "tear jewel" to break his curse. A dying boy named Ishuca enters his cave, and Blood grows attached to him. After Ishuca dies, Blood weeps, creating the jewel that revives him. They travel together, with Blood reuniting with former allies who now oppose him, as demons want him to return to his violent past. Blood vows not to kill humans after revealing his history to Ishuca. Their journey leads them to Toei Cliffs, where they search for a jewel requested by a dealer named Wild.