Kousuke is a tall, slender man with dark eyes and dark hair that is unkempt like his sons’. He is considered to be very handsome and often has a flushed face when he gets emotional.
Kousuke is a very emotional and fearful person. He gets very worried about being loved by his sons and his wife and works his hardest to keep from disappointing them, shown when he went through the trouble of preventing his sons from watching his show as he didn't want to upset them for playing the antagonist of the series. However, Kousuke always tries to make time for his family and loves his wife and children dearly.
Unlike his wife, Umi, he is easily stressed and upset, always being very affected by the opinions his children have of him. His emotional personality is passed onto his son, Kazuma, while his wife Umi's more cheerful personality is passed onto their son, Takuma.
Kousuke is an up and coming famous actor, starring in countless movies, commercials and television shows. His most notable work, however, is his depiction of the character, Boido in the Justice Knight television series that the daycare room children are big fans of.
In high school, Kosuke was considered very handsome by his female classmates and by his friend Kokubo and was a part of the kendo club, quoting that he only joined because he "wanted to become stronger". However, he didn't excel in the club due to his weak and soft nature. One day, while leaving the gymnasium, he came across his future wife Umi (then known as Umi Momoga) doing a gymnastic baton routine in another gymnasium. Entranced by her beauty and kind-hearted nature towards him, Kosuke was quick to fall in love. However, he lacked the confidence to make the first move until Kokubo gave him a Junan Boy* magazine, telling him that if he wanted to start building his confidence, he could start from there. Kokubo had a relative who was running a talent agency, was told in half-jest by that relative to recommend any good-looking person he knew, as Kosuke was "by far the best looking guy" Kokubo had ever seen.
He first appears at Morinomiya, standing in some bushes when he picks up his son. He is mistaken as a pervert by Ryuuichi and Kamitani, causing Kamitani to knock him out with one of his P.E. shoes, before Takuma figures out who he is—to be confirmed by Usaida, who could not recognise him with a mask and sunglasses on.