The protagonist of the tale, Yu-Da, doesn't initially appear to be heroic. Raised by his loving grandfather, who was tragically killed by Foxes when Yu-Da was in fifth grade, he faced ostracism from peers due to his orphan status and residence in a poor area. Even Myung-Ee added to his troubles by expressing anger towards him. Back then, Yu-Da had a serious demeanor, known for kindness without arrogance, though he teased Myung-Ee about her hair and rabbit-print underwear.
Five years later, Yu-Da serves as the Secretary of Chun-Ah High School's student council. His personality starkly contrasts with his younger self; now, he smiles frequently, wears glasses, sports an unusual talisman in his hair, and is exceptionally kind. He acts as a peacekeeper within the student council. Currently living with Se-Eun, Yu-Da is dubbed the "black rabbit" because his liver possesses powers that grant immortality to any Fox who consumes it. Consequently, the student council, comprised entirely of Foxes, must protect him. To ensure Yu-Da's safety, his memories from five years ago were altered.
Whenever Yu-Da's glasses are removed, whether by force or otherwise, he transforms into an entirely different persona known as "Black" Yu-Da. In this state, he dresses his school uniform loosely and unbuttoned, exuding a cold, calculating, and highly confident expression. His "black rabbit" abilities become incredibly potent, allowing him to strike Foxes without physical contact, negating the need for a Ho-Se sword. Additionally, he can manipulate or erase people's memories.
Source: Wikipedia
