Hiya,
I think the only thing from the RTP is the default font, so if you install the font included in the game's files, it should work!
Otherwise, you can download the RTP from this website: https://www.rpgmakerweb.com/run-time-package
Thank you very much! I downloaded the font before but that didn't work, and when I downloaded the thing, the game opened just fine. I played through it all and it was great. The art style is awesome, the sprites are cute, and the story is nicely done. There were a few times where I struggled a bit, but when I figured it out, I was proud of myself. The only things I can really critique about the game is that some areas feel a little too open (or maybe I just don't understand room layouts that much, haha) and if I remember there was a few grammar errors near the beginning. Overall, really great work and I can't wait so see what you do in the future!