um, none of them are required to play the others. I started with the Second Story for Playstation and loved it. The PS2 TTEOT just has bad system implements, from battle to invention, i couldn't stand it. I've yet to beat it because of which.

the SNES version translation is only sub par and some items are left untranslated, but it's okay. I haven't beaten it, but it's a worthy game to play. The story is sub-par, but it is at least entertaining.