Hello there. I've searched high and low for any info regarding the soundtrack of Histudan Hostess. The only thing I could come up with is Squarehood - Departures, which appears to be the ending theme of the movie.
You'll have to get over it, but, I think the composer blended into the background of this one. Probably not a famous person who composed the OST. It's a bit new agey and generic so I'm not sure why you want it that bad to be honest.