Bokuto Kotaro is known for his energetic, playful, and somewhat childish personality. He's described as having mood swings and can be easily affected by his emotions, which impacts his performance on the volleyball court. Despite his emotional fluctuations, he's also a confident and inspiring player, often referred to as the "mood-maker" of his team. He can be blunt but well-meaning, and his enthusiasm is often contagious. He's also surprisingly really smart, just keeping a playful guise. 