I have taken a class on Sashiko. It does lovely stitches, a wide variety. The class was at a local shop where Eve Hawkins, an expert on the Sashiko led the class. Check out the video she has of the hand-stitch machine:
https://youtu.be/WP7kfp3EpMo Also, her website is Bit of Stitch
https://www.abitofstitch.com/