These are plans for the Isuka style tachi kanna, a Japanese scraper plane with a skewed blade. It’s often used to tune up the sole of a kanna, but can also be used to scrape highly figured wood that is difficult to plane. In the Isuka style, the blade is skewed at 7° to the body (dai) to achieve more of a slicing cut than the traditional tachi kanna.
The plans are in Imperial measurements, and use a flat blade and wooden wedge rather than a wedge-shaped Japanese blade.
You can see a video of the build here: