Marumaru Yuu is a supporting character in the multimedia franchise 'Sanrio Danshi' (Sanrio Boys). The series follows a group of high school boys who bond over their shared love for Sanrio characters. Yuu is known for his gentle and friendly personality, bringing warmth to the group. He is particularly fond of the Sanrio character Marumofubiyori (Moppu). Yuu helps his friends embrace their hobbies without embarrassment, promoting acceptance and self-expression among the Sanrio Boys.