Kojima parted ways with Konami, the game studio he was initially a part of in 2015. After he established his independent studio, Kojima Productions, he partnered with Sony Computer Entertainment in 2016 to create Death Stranding. The 2019 game starring Norman Reedus became a critical and commercial success, winning multiple awards.
Recently, rumors saying Kojima partnered with Microsoft for his next project have surfaced. It started when fans noticed that Phil Spencer, the head of Xbox, had Kojima Productions’ mascot, Ludens, placed beside the Xbox logo on his shelf. Were it anyone else, it wouldn’t have created so much buzz, but Spencer is well known for including teases in the background of his office.
Jeff Grubb from Venture Beat reported Kojima was in talks with Microsoft about publishing his next game. Grubb pointed out that Kojima’s involvement with the project will help establish a better consumer base in Japan, where Xbox has struggled historically.
I cannot confirm if Xbox closed the deal yet, but my understanding is that Kojima is the focus of a Microsoft plan to leverage Japanese talent.
Some fans have also speculated that the Spencer tease was just for Death Stranding coming over to Xbox and not actually for a new game. Death Stranding was released on November 8, 2019, as a PS4 exclusive and came over to PC on June 2, 2020.