One Piece: New Order - Chapter 98: Dragon and the CP0 Agent

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

The older young Lisko woke up and found that he had become an American. He took over his father’s ranch and began to live in the United States.

- Description from novelbuddy

While returning home from a boring day of work, a black hole opened up in front of John and sucked him in. Before he was floating in the blackhole, a helmet latched on to him. "Uploading A.I under progress...Activating Survival Kit" A weird robotic sound appeared within the conscious of John and suddenly a white energy enveloped him... After opening his eyes, John noticed he was teleported to a whole new world. A world of magic and he was a user of a system. Arkon, the world John was brought too, was a medieval world which is 10 times bigger than earth. This new world held many new mysteries and this was the beginning of John's adventure. John will dominate and stir the world with his new system. Old technologies begone and use my advanced techys instead! Ha! you want to hold a politic, economical and military war with me? Sorry but my system is too broken for you all to counter.

Suzumiya Kaede, a gamer, fell asleep while playing a game all night and when he woke up he found himself in another world, a fantasy world where using magic is possible! Using his knowledge of games, skills, and cheats, Kaede decides to enjoy as much of his new life in a different world through his newly-acquired magic and sword!