Hell Girl (2005) : 3x17

Upon receiving a request from an elderly woman, Yamawaro begs to be the straw doll. Yuzuki goes to the mansion, asking to speak to the elderly woman but a much younger woman answers the door, leaving Yuzuki confused. Yamawaro explains that in the past, he witnessed the young couple lose their child, Hikaru. After many years, he appeared before the now elderly wife, and the wife believed her son had returned. However the husband, knowing Yamawaro is not human, used him for his experiments to achieve eternal life. When the man feeds the resulting potion to his wife, she regains her youth. However, the wife discovers Yamawaro is being used unethically, and urges him to flee. Now, unable to forgive her husband, she sends him to Hell and commits suicide by exploding the mansion.