I think this is from Simple Modern Sewing (Japanese pattern book)
FREE SEWING PATTERN with TUTORIAL. This is for a beginning sewer who is looking for something different, that's a bit of challenge.and with a more tech look. It's made with knit fabric, so look at Pinterest posts for sewing knit fabric before you start cutting!!! I have a few good ones on my "Learn How to Sew " board ...Chickoteria!