Shushu is a female wolf-person raised believing she was male. Her father later revealed her true biological sex, explaining it disqualified her from becoming a certified wereman. To gain this certification and secure a public servant position, allowing her father to retire, she enrolled at Monster Academy.

Physically, Shushu possesses purple hair and a noticeable snaggletooth, presenting with a tomboyish demeanor. At the academy, she initially concealed her female identity. This secret was accidentally discovered by Juzu, the son of the academy's founder, the monster king. While feared by other students due to his status, Juzu lacked intelligence and simply desired friendship. The exposure of Shushu's secret to Juzu bound their fates together, and the intense scrutiny they both faced from classmates shattered Shushu's hopes for a quiet, low-profile academy life.

Their relationship deepened into a close friendship. This was demonstrated when Juzu, inspired by their teacher Kiisa Fraiger mentioning a "special anime episode law," enthusiastically proposed a December beach trip. Shushu refused initially, citing the cold, the critical need to maintain her gender secret around swimsuits, and the absence of other classmates due to budget constraints. After Juzu's persistent pleading, she reluctantly agreed to accompany him, promising not to swim.

During the beach visit, Shushu kept her promise. Juzu expressed discomfort with the cold but also shared his happiness about experiencing the beach with a friend for the first time. Shushu responded by suggesting they return during the summer.

Her teacher at the academy was Kiisa Fraiger, an adult character with wings and facial markings.