Hokage Becomes A Secret Realm And Joins The Uchiha Clan The Beginning

[Crossing + Different World + Hokage + Mangekyō + Immortal Body + Senior + Invincible]

When the Hokage world became a hidden realm in another dimension, everyone had to enter it to complete tasks and gain abilities to fight against the invasion of monsters. High school student John Smith traveled through time with his memories and resolutely joined the Uchiha clan.

He takes advantage of knowing the direction of the plot and leverages it to his benefit. John reaps huge rewards in the Hokage world and brings them back to reality to enhance his strength.

Sharingan, Mangekyō, Sage Mode, Eight Gates, Flying Thunder God... invincible all the way.

PS: This book has no system; knowing the plot is the cheat, but it is also an invincible, cool story (new subject matter, a combination of reality and the Hokage world, challenging different Hokage scenarios).