Streets of Rage 4 was revealed back in late Aug. 2018, and a year later we finally have confirmation of a Switch version in the works. That means we can talk about all the juicy details of the project, including Yuzo Koshiro's involvement.
Most fans of Streets of Rage absolutely love the series' soundtrack, especially when it comes to the second game. Much of that has to do with composer Yuzo Koshiro, who fans wanted to see involved with Streets of Rage 4 as soon as it was announced. Believe it or not, Koshiro wasn't even contacted to be involved with the game until after it had already been in development for awhile, and Koshiro didn't sign on until June 2019! Check out Koshiro's full statement below, which comes from a Nintendo Life interview.
I wasn’t involved from the start. I found they had already started the project when I got an email from DotEmu. In that email, some screenshots were attached. There was the title screen logo and some characters and background graphics, they had already started the project at that time. Actually, after they revealed the project, I saw a lot of messages from fans on Twitter say they wanted me to join the project.
I met the DotEmu staff for the first time at Diggin’ in the Carts Live, which was held in Paris on September 2018. They came to my hotel and showed me a very early demo of Streets of Rage 4 on a laptop PC. I played the game right away, it was so amazing! The graphics are great! The most interesting thing is the feeling of the actions; it is very close to Streets of Rage 2, which is the most popular title of the series. It was more than perfect, as it also has additional actions as well.
I hadn’t decided to join the project at the time. I met them again at BitSummit in Kyoto in June 2019. There was a first meeting where all the Japanese composers who would join the project got together. They brought the latest version of Streets of Rage 4 to BitSummit. I played the game again at the DotEmu booth and it looked way better than the previous version that I played in Paris, and thought it was great. I admired the game, so after that I decided to join the project.