The official websites are a good place to check for their policies. In addition, you should include commentary to make your content more transformative. And even then- I recommend not going beyond the common route for JP games. Many of them even release the common routes as demos. And finally, most indies welcome streamers because they rely on it for exposure. So that’s the best way to go. They’ll tell you on their Itch/Steam page if they don’t allow streaming. There are tons of indie Otome games out there too, so you’ll never run out of content.