MTL - Rebirth of the Great Entertainment Empire - ~ 1 book recommended by my best friend in the author circle

Failing in his job hunting, Sanada Kyouichirou was hopeless in this society. When kyouichirou had thrown himself towards the bottom of a cliff. When he woke up his body had returned towards when he was in fifth grade of elementary school. He did not want to have any regrets in this life so he had decided on building up an harem in this second life.

The elder sister that he admired, a senior and president of the student council at a school for rich young girls, a strong minded upper classman at school. The poison fang of Kyouichirou who had pretended to be a innocent child attacks those girls.

[R-18, Mature Element Warning!] [Multiverse!]A young man with a questionable job dies, eaten by a shark. To his surprise, afterlife was a spinning roulette that decided his next world and powers, with an annoyed Goddess supervising the process.The Gamer System welcomes him with open arms, and he shivers in the endless potential it holds. If used right, he knew The Gamer could step beyond even Godhood. Beyond God.Out of desperation, that was exactly what his goal became. The Goddess was a snitch, and now she and her fellow Gods wanted him dead. What, and why?In the end, [Soul 799], soon to be renamed as [Neji Hado], becomes a Cursed Soul.-—-Tags: Gamer-System, Gray-MC, Harem, Incest, Mature, Multiverse, R-18, OP-MC, World-Hopping.First World: My Hero AcademiaSecond World: NarutoThird World: Fate/Grand OrderFourth World: High School DxD

Su Yu was in a third rate university when the “Sky Holes” appeared, his school fell through the “Sky Hole” and appeared in the middle of a forest that was teeming with terrifying creatures.

Li Muyang had transmigrated, and the good news was that he had a system. The bad news was that this system could only be used to play games. Oh well, if it’s playing games, then so be it. It’s better than having nothing. In the game, he was powerful and mysterious, causing the extraordinary fairies to be shaken to their core. Since it’s just a game, there’s no problem in aiming for the full compendium route, right? It wasn’t until one day that the fairies from the game showed up at his door that Li Muyang was truly startled. What was supposed to be just a game, how did it become real? “So... listen to my excuse!” I was really just playing a game!!