The game is completely Identical in terms of events and requirements, so any walkthrough will do. (Confirmed through the Underground)
Hence, any of these fine walkthroughs should help you through the game:
http://www.gamefaqs.com/portable/gbadvance/game/929937.html
Please note that Most boss battles have had difficulty upgrades so previous strategies may not work
Points where you might get stuck without knowing the game and/or japanese, there are no spoilers below:
*In Fabul Castle (the one with all the bald monks if you can't read katakana), after the crystal scene, you must go to the Inn to progress.
*After you free a certain character from being mind controlled by soldiers, the key he gives you opens a shop AND a secret passage near a well…
*After Cid leaves your party, you need to go to Baron Castle and head into the eastern wing of the castle. Talk to the two workers in the area.
*After a mid-air meet-up with Kain, you need to head to a city covered by forest. Head north of there to find what you need…
*There is a certain dungeon where you may find yourself paralyzed. Unequip any magnetic armor/weapons, and you will be able to move freely.
*After you get FuSoYa, the room above him seems to serve no purpose. Come back here after the next dungeon.
*After the Giant of Babel, there is a new story line, were you are learning of cecil's past playing as a certain character, leave the house and go talk to a man near a pond.
