From Wikipedia:
Chumchurum means "like the first time" (pure) in Korean. Chumchurum is becoming popular to mostly women because it is softer than other alcohol. Chumchurum contains 19.5% of alcohol and it is made of alkali water, which makes soju become more distinct. Because of this, the company explains that it makes the soju taste better if you shake it well before drinking it. Soju is a clear, colorless distilled beverage of Korean origin.