|Allies||Ayako Kajiro, Hisako Yao|
Originally a distant relative of the Kajiros, as a child he was adopted into the family in order to continue it, since only girls are born to the Kajiros. He was the older sibling of Ayako and Miyako but his relationship with Ayako later became more than just siblings. Along the way he proposed to her and were engaged, but he was well aware about the sacrifice to the alien god in the Kajiro family, hoping that Ayako won't be sacrificed and Miyako will.
In 2003, the ritual involving the Kajiro sisters in Hanuda was interrupted by Kyoya Suda and it failed, causing the village to descend into an alternate world with shibito and red water. The others who attended the ritual—Jun, Hisako Yao and Kei Makino—ran off and got separated while Miyako had her chance to escape from the sacrifice. Jun did not want his fiancée to die in the ritual so he sought to find Miyako before it was too late.
By the time he found her on Day 1, she fought back knocking him out and escaped with Kyoya. On Day 2, Jun returned and shot Kyoya, who fell down the hill, allowing Jun to get Miyako, and he did not let go until Hisako found them. On Day 3, the ritual resumed and Miyako was sacrificed. Hisako told Jun she did not need Ayako so she had her killed, which was not what Jun expected. The sacrifice of Miyako resurrected the alien god Datatsushi, which also killed Jun. In the Inferno, he was reanimated as a shibito that served and defended Datatsushi from his attacker Kyoya with the Homurangi sword but was destroyed by the Uryen.
Having been chosen as the next head of the most distinguished family in the village, he is intensely conceited and arrogant, due to being raised with all of the family's power at his fingertips. He also has a sadistic side to him, being infatuated with Miyako even though he knows his betrothed's feelings for him.
Jun aspires to, if possible, become the world's messiah if he can get hold of the Kajiro family secret (the curse of immortality), and for this reason he assists with the ritual so he can see the god's revival with his own eyes. He shoots Kyoya with intent to kill out of hatred and jealousy, but in the end, pressured by the awakened Hisako, he helps with the ritual and finally turns into a shibito after being attacked by Datatsushi.