Leader of the SEPB branch (also known as East Central Branch) on Ouka city. He is somewhat cunning and looks untrustworthy, but has the ability to use human resources to the extent and hold off enemies both from outside and from within. He is also the one who picked up Daisuke and bring him to SEPB, also the one who sent Daisuke to defeat "Snowfly" four years ago. Although not totally agree with his way of doing things, Daisuke does respect him and would follow his order. His sister, Senri, lives by eating away his dreams, a fact only known to him and Daisuke. He was wounded during the operation to defeat Mushibane and Ladybird. He remains unconscious since then. It turned out that he was faking his unconsciousness for the whole time, and sneakily planning ways and gather personnel to overthrown the absolute power of Central SEPB Branch lead by Yaeko Miguruma and defeat the "Original Three" and "C" with minimum sacrifice. He woke up in Volume 13. After the last battle against "C" and Oogui, Keigo reformed the SEPB to recover the damaged caused during battle and to prevent the interference of foreign force. He also works his hardest to ensure the surviving Mushitsuki gets the right treatments and reorganizations.