You'll probably need a Tile editor at some point. I use Tile Molester (requires Java).

Also, since it's a GBA game the text might be in Shift-Jis or EUC. Try using one of these tables first, it may save you the time of building your own table
http://www.romhacking.net/docs/179/
http://www.romhacking.net/docs/178/

Which game is this? I don't really follow the series much. Though I've heard a GBA one was ported to DS for its US version.

That looks like nothing but raw data. What you're looking for is Japanese text. I recomend you use WindHex, because Thingy is old, lacks many features, and outdated. (Load your table then make sure you have View Text Data as Unicode enabled in options in WindHex)

Here's a screenshot of Japanese Text in the GBA game "Monster Summoner"



Remember, sometimes you wont be able to find any text, some games compress their text or store it in a strange way. For games like those a more experienced hacker would probably be needed.

I'm a beginer hacker myself and can only do simple hex editing for games that store their text in a non-sneaky manner. There's been many games that I've wanted to do, but later on discovered that it is way over my head.

Try installing this:

http://office.microsoft.com/downloads/2002/ie_ja.aspx