Mr. Nian, Your Wife Refuses To Be The Substitute - Chapter 1111

At the age of 12, Naruto Uzumaki gained the extraordinary ability to traverse between his home world, the Ninja World, and the mysterious world known as the Soul Society.Naruto's DiaryKonoha Year 63, March 15: I seem to have died [crossed out] I seem to have died and come back to life.Konoha Year 63, March 16: The weight of this new existence crushes him. A return to life offers no solace, and he questions whether it might have been better to remain dead.Konoha Year 63, April 1: Desperation sets in as Naruto searches the Soul Society for his parents, only to discover that this world is not connected to his own. His parents are nowhere to be found.Konoha Year 63, July: The dream of becoming Hokage fades, as Naruto finds himself detached from the village that once held his heart. The desire to become a Shinigami grows stronger within him, spurred by the hope of discovering the true Soul Society of his world and reuniting with his parents.

Childhood sweethearts.
The most popular person in school is my childhood sweetheart.

- Description from Novelupdates

When Ye Mo suddenly woke up, he realized that everything around him seemed to have changed: He has been transmigrated into the modern Earth where spiritual energy is scarce. His pretty master from his former world was nowhere to be seen. Most importantly, he found himself in the body of a young man who has been abandoned by his clan for an embarrassing reason…

- Description from Novelupdates