Did the guy have the ability to switch bodies all through his life?
That's fatty boy woke up miracle in a new body. It's like two body one soul. When one body sleep then another body activate.
I think you can get some idea if you watch the trailer of it.
Generally I don't share Movie or Anime review although I am a Anime lover. It was the first time I shared a review. In fact I think it would be crime if I don't share it and finally I decided to share it.
I must recommend you to see this. Home season will take 160 munites maximum but I hope you won't regret for it.