>In Generation I and Generation II, Bill's system can store
20 Pokémon per box, while there are 12 boxes in Generation I and 14 in
Generation II. (In the Japanese versions, 30 Pokémon can be stored per
box, and there are 8 boxes in Generation I and 9 in Generation II.)
So in both English and Japanese versions of Pokemon Yellow, you can store 240 Pokemon. Although the bifurcations of number of boxes and capacity of box is different.
Hope I helped!