Shiro was taken into a home by an old woman named Masae. After her only son, Shou, saw Shiro in his transformed state, Shou called Kitarou for help. After confronting Kitarou, he found out that he was a youkai that drains the life energy of humans. This explains why Shiro feels better after rubbing against humans and why the humans he spends time with end up dead. He refuses to believe Kitarou and Medama-Oyaji and returns home to Masae, only to take off again after she gets worse upon touching Sunekosuri.