Are there specific rules for dating apps?
Otherwise - no, you don't need a US LLC. You just need the US taxpayer number. This looks a bit intimidating but it's not difficult. The most challenging part is spelling your foreign address over the phone. Get a "NATO Phonetic Alphabet" on the screen before you start! The person I dealt with was very friendly. Have you ever been though US customs/immigration? - it's the exact opposite experience. When the US govt recruits people, if they are arseholes they send them to immigration, and if they are lovely they send them to the foreign tax registration helpline.
There used to be something odd about tax in Japan but I think that has gone.