MTL - My Classmate is 200 Million Years Old - Chapter 105 Guest Reens.

After picking up a phone on the streets, Feng Yuchen was sent to the world of High School of the Dead. He, along with 100 people, have to travel through various worlds, fight and solve quests in order to survive.

Whoever dies in that world, would be teleported back to the real world without memories of what happened before and die in an accident one year later.

- Description from Novelupdates

Kuramoto Daisuke, a freshman in High School was suddenly exposed to someone vanishing in front of him. Turns out he was admitted to a Special Class full of Isekai Heroes that were regularly summoned to Otherworlds since the start of their Middle School. He was told that he was to become their Support to prevent each of the Heroes' fate of dying in the world they were summoned into. Though mediocre, he realized that his ability has a great potential but it needs a lot of hard work on his part.

Unconvinced of being just the Support Character, he vowed to excavate his mediocre ability, all the while supporting the Heroes using it.

And maybe more.

Chen Yan travels between worlds, ending up becoming an honorable prince in a medieval fantasy world. Yet this world was not quite as simple as he thought. Witches with magical powers abound, and fearsome wars between churches and kingdoms rage throughout the land.

Roland, a prince regarded as hopeless by his own father and assigned to the worst fief, spends his time developing a poor and backward town into a strong and modern city, while fighting against his siblings for the throne and absolute control over the kingdom. Join Roland as he befriends and allies with witches and, through fighting and even farming, pushes back invaders coming from the realm of evil.

- Description from Novelupdates

At the age of 15, He Jin found himself a “husband” in an online game, their love was filled with loving affection and sweetness. However, because his study was being interfered with, his parent cut off the internet, he didn’t even have a chance to say goodbye and had to disappear from the game.