Is shochu related to soju?

I used to live in Japan, and I miss shochu, but it’s irritatingly difficult to find. Soju, on the other hand, is abundant in the States, so I’m wondering if they’re similar. The names obviously sound similar, and given the extremely large number of Japanese foods and beverages that are derived from Korean and Chinese cuisine, it’s not far-fetched to assume that shochu began as a loanword for soju. However I cannot find any concrete info online, only a handful of meandering articles that I am 80% certain were written by chatGPT, so I figured I would come to the last good forum on Earth. Please help me, alcoholic redditors!