A minor character in the Confession Executive Committee: Love Series, and Haruki Serizawa's deceased older brother. Chiaki and Haruki look one and the same, but his hair is slightly messier than Haruki's. He has blond hair like his brother, but his roots are brown. In the anime however, the brown roots are done away with and his hair is completely blond. He once saved a girl from drowning. After that, he died from his unknown sickness.
His school uniform is worn open.