You had me sniffing my tea to see if anything had been slipped into it. Well done!
I love that you incorporated some humor into this trippy ending.
“Worst. Theme park. Ever,” the girl declared, drawing Shiro’s attention away from the sign. She laughed. “But really, this is a weird dream.”
I don't know. I've heard of worse, LOL!
There's a lot to wonder at here with your descriptions and how you moved the story along to make the day even odder than it was for Shiro in the beginning.