Tentang
First appeared in Dead and Seek. Is Momo's homeroom teacher, as well as Ayano's father and adoptive father of Kido, Kano, and Seto. He provides both stern and kind guidance to Momo, who cannot come to school often due to idol activities. Even though he has lost his family in the past, he still continues to do his best in educating students. He possesses the power of "making eyes clear."
The Snake of Clearing Eyes
During a field study on August 15, he and his wife, Ayaka, get caught in a landslide and die. They are transported to the Heat Haze, where Ayaka is left behind, while he is possessed by the Snake of Clearing Eyes and sent back to the real world. Feeding on his wish to see his wife again, the Snake of Clearing Eyes controls him at night to conduct experiments, and even go as far as to hire agents to do his bidding. During his possessions, he kills Takane and Haruka as sacrifices to bring more snakes to the real world. During each timeline, the Snake of Clearing Eyes moves from his body to Konoha's so killing the Mekakushi Dan would become easier.
About a snake inside him:
Kenjirou's snake, however, is evil and malicious. Because Kenjirou is its "master," it intends to obey his desire, which is to meet Ayaka again. It can go through drastic extents to reach its goal, such as killing Kenjirou's precious students Takane and Haruka.
Status
In the true ending, once Mary opens up the Heat Haze to the world, he is reunited with Ayaka and decides to stay in the Heat Haze with her.
(Source: Vocaloid Wikia, Kagerou Project Wikia)