Story of: Naruto: Beginning Summons a Parallel World
“Ding dong, Namikaze Minato (blackened, road crazy version) is summoning… ”
“Ding dong, Uchiha Mikoto (demon version) is summoning… ”
“Ding dong, Tsunade (young, foodie version) is summoning… ”
Liu Dao accidentally traveled to the world of Naruto and was bound to the parallel time and space summoning system, which can summon people from various parallel worlds of Naruto.