I just tested the Linux release of Shadow Warrior (remake), and noticed that it has a game opening which I didn't see before, when I played it in Wine. May be it's a new addition, or it just didn't work in Wine - not sure, but I don't remember seeing it.

There is a song playing there in Japanese. Does anyone have an idea what song that is?

It's "Kawaii Hana": https://www.youtube.com/watch?v=XIh4ttI7mP8

I found the exact version of it: https://www.youtube.com/watch?v=uyLA5Nb9J7g