Koori no Mamono no Monogatari Gaiden

A demon named Blood, who had been imprisoned in ice for decades, is seeking the "tear jewel" in order to lift his curse. A dying boy named Ishuca visits the cave, and touched by his kindness, Blood becomes attached to him. After Ishuca dies, Blood weeps, and in doing so creates the jewel that revives him. They travel together, and Blood reconnects with former allies who now oppose him because he refuses to return to his violent past. Blood confesses his history and vows not to kill humans. Their journey continues as they head to Toei Cliffs to find a jewel requested by a dealer named Wild.