When I was learning to read Japanese the Hiragana alphabet was displayed in a somewhat periodic table-esque format. The vowel ending sounds were the vertical ax

When I was learning to read Japanese the Hiragana alphabet was displayed in a somewhat periodic table-esque format. The vowel ending sounds were the vertical axis (a,i,u,e,o) then next column was ka, ki, ku, ke, ko - then sa, shi, su, se, so etc.