Wasabi is good for you! Wasabi was originally included in sushi to ward off food poisoning for it’s antimicrobial properties and deodorizing effects since as early as the Asuka Period (592-710) - but for the more health conscious modern person, it may also be appealing that the fiery green plant is also packed with potassium, calcium, Vitamin C and phytochemicals that strengthen antioxidants in your body and help your skin fight free radicals.
The skillful chef would start with a block of Daikon radish around 10cm (4 inches). After the skin is peeled, they will make a thin long continuous strip of radish, using the knife in a circular motion - this skimming technique is called 'katsura muki' 桂剥き. The image shows how transparent this slicing is, it takes a lot of practice and wrist technique.