Their first appearance is when Rukia kuchiki is sent to the soul society to be punished for staying in the human world. But ichigo is determined to save her. Kenpachi vs Ichigo

This is the epic battle between Kenpachi and Ichigo. Kenpachi is informed by his second hand man that ichigo had defeated him and he is strong. Kenpachi is interested by him and searches for the "Rioka". After Uryu's fight with his grandfathers assassine, he finds a greater enemy. Ichigo realizes that Kenpachi is way stronger than him and runs away. But he realizes that he cannot back down and must save Rukia. Zangetsu/his zanpakto starts to speak to him and convinces him to stop running and fight. In the end the final blow had made it a draw. Gin vs Toshiro This takes place after captien izan is dead. Momo is trying to figure out who killed him and does. Momo escapes from her cell and looks for Toshiro. The note left for her said that Toshiro Hitsugaya was the assassaine to captein Izan's death. But Toshiro disagreed and said Gin Ichimaru was the killer. Momo was mad so she didn't listen. Toshiro wanted to fight Gin, but he had to knock out Momo. Gin and Toshiro are about to fight after this. Toshiro said if you hurt Momo he would kill him. But the match ended in a draw.