If you understand Japanese, you can search for a game and it will return the game’s official website. I think it covers both commercial and indie releases, but I know for sure it covers indie.
Explanatory post, not a shaming post for those who like red flag LIs. Found this useful for anyone who wants to understand—I certainly read a lot of similar explanations from fans of red flags in otome during my time on Reddit. Also useful for engineering an LI for your own game 👀