Yorito Nagai

A private in the Japanese Ground Self-Defense Forces, Yorito crash-lands on Yamijima Island along with Takeaki Misawa and Hiroshi Okita, who dies on impact but is quickly resurrected as a shibito. Lacking in field experience, Yorito follows Takeaki until they are separated when the Siren sounds. When he next encounters Takeaki, the major has become mentally unstable, threatening to kill Ichiko Yagura. Yorito kills Takeaki in order to protect the girl, but his attempts backfire when the possessed Ichiko attacks him. He eventually joins up with Mamoru Itsuki in climbing the Spider's Thread, but falls off and is confronted first by the yamibito versions of Hiroshi Okita and Takeaki Misawa, and finally Otoshigo. When the red wave hits, he then falls into the yamibito dimension where he sees them walk around as if normal people. Unable to tell if this is reality or an illusion, he is driven insane and embarks on a killing spree.