The presentation was aesthetically pleasing, and I liked the music a lot. Great use of backgrounds. Also, a ruler isekaied into Gensokyo as a cute girl? Nice. It's a fun concept.
One thing I noticed is that the story felt a bit fast in the later half, mainly around her integration into the world. Maybe it's because the time skips weren't made explicit, but that's the impression I got. But overall, it was an enjoyable read. Good job! And nice Sakuya kissing.