Koichi is Ray's first love, revealed in a flashback to have proposed escaping with Ray from the farm where they were raised. He has been missing since Ray's rescue, making contact with Ray in episode 7 from an unknown location requesting to meet with her. He makes his first physical appearance after One attempts to kill Ray, though he still does not allow Ray to get close to him at that time. It is later revealed that he is a clone of the H Ring Man and was working for him, and the reason he was willing to do the bidding of the person he despises most was to track down Ray and to create a utopia with her by recreating life in the "white room" which included gathering all of the numbers and restoring Ray to her original self, which involved returning her original eyes which were implanted into Sumire. He grows increasingly maniacal throughout the series, and despite his insistence that he is nothing like the man he was cloned from, he shows the same level of obsession with Ray, who genetically is a clone of the H Ring man's mother. After he kills Red Ribbon, who makes a jealous attempt at Ray's life with a scalpel because of her unreciprocated crush on him, he commits suicide by shooting himself in the head, believing that Ray has died.
(Source: Wikipedia)