A Hospital in Another World? - Chapter 95

In a world where human and monsters relied on mystical fruits and their inner power to fight for dominance, a lost soul was thrown, given the powers from all the other worlds he’s known. But there was a catch; he had no control over what power he would get! With knowledge beyond that of most, he sails his path to the top of the one piece world!

- Description from Novelupdates

Leiyin accidentally crossed into the One Piece World, and accidentally obtained the Naruto System.

Because of a mission, Bruce White entered prison as a criminal, but his family was abused and bullied as a result. After three years of life in prison, he finally completed his mission. Yet, he received truly shocking news when he came out of prison. His father had passed away, his mother went missing, but he knew nothing about it. Filled to the brim with rage and grief, Bruce gathered his forces and headed towards the city as fast as possible.