A blade shorter than one shaku is taken into account a tantō (knife). A blade for a longer time than 1 shaku but less than two is taken into account a shōtō (small sword). The wakizashi and kodachi are in this group. https://arranypac112297.blogdun.com/31279427/how-much-you-need-to-expect-you-ll-pay-for-a-good-katana-for-sale