Kousuke usually shows a cheerful personality, though he is a fairly serious person and when angered he seems cold. Usually, he is in a good mood. At times, he can be perverted and lewd. Kousuke has a tall, muscular build, with black hair and blue-gray eyes. He also has a mole on his chin. Kousuke has always been fond of math and solving all problems possible, as stated by his mother, he has been sick because of solving a problem without sleep. It is also stated that he likes to care and help.