Cat-Eyed Boy S01 E02 The Long-Neck's Tomb

Our lonely, scorned hero interrupts his quest to find his birth mother to save a village from a monster called the Long-Neck. The Long-Neck demands an annual sacrifice of a young maiden to quell his appetites. Because this year's victim, Shizue, resembles his foster mother, Cat-Eyed Boy decides to fight the evil fiend before continuing his journey.