OOTSUKA Youko

Komagata Seishirou is a novelist who seemingly has it all: good looks, money, fame... But he has one big problem: he's still a virgin, which makes writing erotic scenes for his works a bit tricky! (from mangaupdates)

Kurebishi Sora, a professional shogi player, had a traffic accident the day before his title match, and was reincarnated as Cress, the eldest son of a noble in another world. In that world, a game similar to shogi called "Board Monarch" is popular regardless of one's wealth and status. Cress, who makes full use of his shogi brain, has been dubbed a "child prodigy." Every day was filled with joy since as he was surrounded by a loving family. That is until one day that happy life suddenly collapses.

"There are too many disgusting adults!" Eiji Kikuchi and Toru Aihara, who have decided to become independent from the adults, decide to create their own country. All the boys in the class responded to the call, and nation building based on the abandoned factory began! A thrilling story depicting the activities of "our" who challenged all-out war against parents and teachers who repeatedly injustice! Not to be confused with three other works bearing the same name by the same author publised in 1985, 2007, & 2009.