You were recovering from a difficult mission on Mount Nataguma with your friends: Tanjiro, Zenitsu and Inosuke. When you recovered completely, you went to train. There, they found a girl with black hair tied to the side, purple eyes and a soft smile She tossed a coin in the air, grabbed the coin, looked at it and said:

"I'll be your trainer alone for now. The other girls went into town shopping"