Does The Orange Make Me Look Professional?

Ichigo beat Aizen but something went wrong. Suddenly he finds himself trapped in another world where magic exists and dragons are more common than they were where he came from, meaning they actually have the fucking things. He's found, saved and befriended by four powerful wizards(He couldn't stop laughing when they first told him) and just continues to live through this new world. His discovery that he was immortal wasn't as much of a shock as he thought it might have been if he was still back home. He watches the kind four grow old and eventually die, but not before entrusting him with their most prided possession.

The position of headmaster at their newly established school of witchcraft and wizardry.