This variation of stem stitch family looks like satin stitch. The technique used is that of outline stitch, the only difference being that every successive stitch is made within a short gap difference. The tutorial will make it clearer to you.

I will work on an open space to demonstrate this stitch. This stitch cannot be carried out like the other stem stitch varities, in a straight line. Japanese stitch can be used for simple fillings of geometrical nature. It is generally used to depict larger areas of landscape like, water.

japanese_stitch_1      Fig 1: Bring the needle out through A. Now, put the needle in through B and bring it out through C.This process is similar to outline stitch. Only, make sure that C lies at a closer distance to A, and not exactly between A-B like it would in outline stitch.
japanese_stitch_2   Fig 2: Continue this process of stitching.
japanese_stitch_3   Fig 3: A finished series of this stitch would look like this. You will see that though it uses the outline stitch process, it looks like satin stitch.