Supernatural

On a school trip to shinobi-themed Ninjatown, a young man named Ichi Kuno accidentally springs a mystical ninja trap which sends him back to the Age of the Ninja. Having no other path, he must pose as a girl and infiltrate an Kurenai Academy, a school of kunoichi students, to retrieve a mystical scroll that can return him to the future. But when everyone around him is already far better at stealth and infiltration than he could ever imagine being, it's not going to be easy.

It details the life of a mid-rank soldier who died at the very end of the war against the Demon Race. Fortunately for him, he wakes up to find that he is a baby again, in the embrace of his real mother, years in the past. Determined to avoid the chain of tragedies that took his beloved ones away from him, he takes advantage of the advancements in swordsmanship and magic that developed during the war (as we all know, wars are when many scientific breakthroughs tend to happen), and tries his best to prepare for the demon invasion as well as strengthen himself with maximum efficiency.

After dying, Sena Kaito was reborn in another world and confronted with a peerless beauty, Elisabeth, who had appeared before his eyes. Introducing herself as "Torturchen," she commanded Kaito to become her servant, but he refused on the spot. When Elisabeth presented Kaito with the choice of either torture or butler, he immediately submitted and began to serve at Elisabeth's side, to accompany her until she completed her mission.

Ah-Li is the apprentice of the Daoist Qiu Jue and they roam the country exercising demons
It is not until they reach the capital that they hear of the suspicious ghost mansion owned by the seemingly richest man in the capital!
Just what is going on in there?
Ah-Li will not rest until she finds out (though her master really doesn't want to bother about it?!)

man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it.

Kyu was abandoned alone on the surface. After wandering, Kyu finds a boy who lives in an isolated snowscape.

U19

Year 2036, Japan is under the adult party power and make children's life miserable. But for "rebelious-edgy-teenager-with-funny-scar" Kudo Eiji, It doesn't matter because he has his childhood friend Akari to cheer his everyday life. For Eiji, Akari is his emontional mainstay. Someone that can make him calm.
But then, one day adult party decide took Akari and transfer her to another school. It emotionaly stress Eiji out. Little did Eiji know, this awaken some power inside him

Alice Ryouhei will leave high school soon, but he's trying to avoid thinking about his future. Late one night, when he's hanging out with his tough friend Karube and his silly, girl-crazy friend Chota, they see fireworks. After one blindingly bright explosion, they find themselves waking up in a different world. In this 'Borderland,' people are forced to either participate in potentially deadly games or simply die. Will Chota, Karube, and Ryouhei be able to survive this dangerous new world, and is there a way they can get back to their original lives?