He was a surgical genius, but a snow-mountain accident ruined his career and claimed the life of his younger brother, Masato. The accident also left his right arm with severe frostbite, which left surgeons no choice but to amputate and graft the arm of his deceased brother. The incident ultimately resulted in Kino's surgical license being revoked. From then on, Kino would suffer psychotic episodes stemming from the traumatic event. Kino was also one of the passengers aboard the “Akatsuki” and among those awakened by the "Overlord of Light".
Over time, his powers would "evolve" into Another Agito. But given his unstable mental condition, he would eventually became corrupted by his newfound power, and soon became convinced that he alone was all that was needed to defeat the Lords. His delusions of grandeur ultimately motivated him to try and eliminate the real Agito. Though the actions of his brother's arm would occasionally interfere, it wasn't until his defeat at the hands of Kamen Rider Exceed Gills that Kino became humbled. From that point on, he would aid the other Riders, even after the Overlord stole his power.
He later performed a small surgery on Shouichi in attempt to remove the quill of Ericius Liquor from his body, during this Kino admitted that he had become corrupted not because of the Agito Seed, but rather his own weakness as a human being. After that Kino was able to recover his power thanks to Shouichi and help the group defeat the Ericius Liquor. After the fight, Kino goes with both Majima and Ryo for a cup of coffee, and encourages Majima that he can become a Doctor before finally dying from the injuries sustained by Falco earlier. However he died with a smiling face, after dreaming of being able to save his brother during the snow-mountain accident.
Kamen Rider X
Kamen Rider Amazon
Kamen Rider Super-1
Kamen Rider ZX
Kamen Rider Black/RX
Kamen Rider Kuuga