Why is this chord spelled weird?

https://preview.redd.it/3ydjm3tedwke1.png?width=1366&format=png&auto=webp&s=7f86d0a7fe4cc231b6fd96d7d85d107fd9c52c4d

It just sounds like a minor 4 (of the relative major) to me, so why is it spelled C D# G instead of C Eb G? It even resolves downwards to D♮!

Piece is "Autumn ... Dream Song on November" by Takashi Yoshimatsu