Kohei Ooike is a supporting character in the anime Dan Doh!! He is a childhood friend of Tadamichi Aoba, known as Dandoh, and Yuka Sunada. The three are initially standout players on their elementary school baseball team, where Kohei distinguishes himself with a powerful swing capable of hitting the ball further than Dandoh. This natural athletic ability provides a strong foundation for him when the trio is introduced to the world of golf by former professional player Shinjo Mikiyasu, following an incident with their school principal.

In the story, Kohei serves as one of Dandoh's closest companions and a fellow competitor. He represents a steady and reliable presence within the group, offering grounded support as they navigate the challenges of learning and competing in golf together. His loyalty to his friends is a primary driving force behind his actions; he follows Dandoh into the sport and is fully committed to improving his game alongside him and Yuka.

Kohei's personality is marked by his determination, friendliness, and diligent work ethic. While he is a natural athlete, he applies himself seriously to mastering the technical aspects of golf, showing a grounded and realistic understanding of his own abilities. His personal development throughout the series involves the transition of his raw physical strength from baseball into a refined and effective golfing technique.

Kohei's abilities on the golf course are notable for their blend of power and precision. He retains exceptional driving strength from his baseball days, allowing him to consistently cover great distances off the tee. Complementing this powerful long game, Kohei hones a distinct talent for putting, making him a precise and capable scorer on the greens. This combination of raw power and delicate touch makes him a well-rounded and competitive player in tournaments.