Following ash-glazed bowls chronologically shows the genealogy of jo-yachi.
Ash-glazed bowls include three types: those making a straight line from
the foot to the rim (Style I), those curving inward (Style II), and those
warping outward (Style III). According to the classification, style I is
found in the early works of Wakuta ware, style II in the works during the
unification of the three kilns, and style III in the early works of Tsuboya-yaki.