Kako was a spoiled and self-centered coward with a severe inferiority complex. He acted as an errand boy for a group of bullies to avoid being the subject of their abuse, and his parents would let him get away with just about anything, much to his older sister's chagrin. Kako’s only "friend" was Kirie who also went to his school. Kako would constantly boss Kirie around since it made him feel less like a loser especially since Kirie would take this abuse without complaint. Kako in fact made Kirie accompany him to the nature school for this very reason. It was here that Kako developed a strong crush on Chizu. When he first entered the game Kako was excited, hoping that his piloting Zearth would make him famous, but upon learning the price of piloting, he suffered a mental breakdown and hid in his room.
His mental state was made even worse when Dung Beetle visited him and told him that the other pilots were leaving him out of the loop and that he had so little time left. This pushed Kako overboard, and he went over to Chizu's house with every intention of raping her, but she stopped him at knifepoint. Moments later he and the other pilots were retrieved by the JSDF. While being held there, Kako experienced graphic nightmares involving him beating up on the bullies who would use him and raping the female one, or beating his sister and Chizu while they mocked him. When the battle against Fig began, Kako hoped that the interference of the Self-Defense Force would mean he wouldn’t need to pilot and die. This hope was dashed when the futility of the JSDF's attempts were made apparent. Kako then panicked and started running from the battle with no intention of stopping. The group was at a loss trying to find a way to get Kako to fight, but it was Kirie who finally spoke up and made a comment implying Kako's cowardice. This comment drove Kako into a rage and he began to mercilessly beat Kirie. Chizu stepped forward and stopped this display by stabbing her knife into Kako's throat and slitting his jugular. His death was unceremonious; it is the first death where no tears were shed. His chair was a straw and cloth beach chair with a wooden frame.
In the anime series, Kako did not even pilot Zearth. After he was visited by Dung Beetle, he tried to make a move on Chizu by inviting her to visit an aquarium together, but she refused. When he was selected as the following pilot, he panicked and disappeared. Chizu found him in the aquarium and tried to cheer him up, but when he tried to force his way on her, she pushed him and he fell from a stair, rendered unconscious. Chizu fled away from the aquarium leaving him behind, when it was destroyed by a missile fired during the battle between the military and the enemy robot, and Kako, just after recovering his senses, was killed by the debris. The children discovered what happened when his lifeless body was teleported to Zearth's cockpit with them, and Chizu claimed the responsibility for his death, before being selected to replace him.
