As a sprinter, he has a competitive nature, and easily gets upset or disappointed when he is beaten in a race. He considered Imaizumi his rival, and therefore gets particularly riled up when he thinks that Imaizumi is winning. He also gets this way with his mentor, Tadakoro Jin, who he often tries to beat in sprinting. He is something of a brother figure to Onoda, whom he hangs out with often since they joined the cycling club together. Naruko is known for being "flashy;" he likes to stand out and thinks those who don't are dull. This flashiness encompasses his appearance as well as his cycling style. That's why he takes pride in being a sprinter; he thinks that the fastest is the coolest.
