Lemon is a humanoid classmate of Naoko Watanabe, characterized by bright yellow skin and black eyes. She typically wears a purple dress with a matching bow in her hair. Lemon frequently provokes Naoko's anger, triggering Naoko's transformation into Gauko. Her mischievous behavior includes spreading rumors and mocking others, often creating conflicts within the class. Lemon is driven by a love for gossip and a tendency to instigate trouble.

Despite her antagonistic role and the recurring arguments, Lemon maintains a soft spot for Naoko and displays loyalty and protectiveness toward those she considers friends, actively defending them when they face trouble. Naoko expresses strong animosity toward Lemon due to Lemon's role in making her life difficult. Lemon balances these disruptive tendencies with moments of genuine care and solidarity.