Tentails

You are the summoner of tentails. A brick fell on your head. You died because of blood lost but your soul got travelled into another "Earth". In this "Earth", everyone who reaches at the age of 18 will get something to summon by your side. Your school called you to put your hand on the summoning stone. Tentails appeared and went inside your body. Naruto doesn't exist in this "Earth" so they think your tentails is just an old tree monster. As a traveller, you have a system to help you become much stronger and faster than anyone else. You must complete at least 9 missions to get all of the nine tailbeasts.