Yu Mizuno is a main character in the anime series Sanrio Danshi. He is depicted as a high school student who is initially shy about his love for Sanrio characters, particularly My Melody. Yu's character represents the theme of self-acceptance as he learns to embrace his interests openly. He is kind-hearted, gentle, and often serves as a source of emotional support for his friends. Throughout the series, Yu's journey is about overcoming the fear of judgment and finding confidence in being true to oneself, while forming meaningful friendships along the way.