I decided to take a crack at this myself and was able to, from what I can tell, dump ALL the characters not already here, which it turns out is a good few. Puar, Fortuneteller Baba, and Giran are probably the most notable so far. I have just submitted three new sheets but I'm still working on another two.

I can't get the game to actually run unfortunately, but going by file names it labels sprites as either "bchara" or "field" characters. "bchara" seems to mean Battle Character which would imply the "field" ones are just overworld NPCs, but confusingly, looking at screenshots of the game, some that are labelled "field" with no "bchara" sprites appear as enemies. So Field sprites can also be used as enemies, making it kind of impossible to tell which field characters are actually enemies and which are only NPCs.

I decided instead of guessing which are which to just group them together by which file name they use in the new sheets

Don't expect too much more out of the rips here, I've basically shifted through the entire game's data. Most stuff just will not rip right, and it's a major pain. Everything up right now (and the 2 pending sheets as of this comment) are the stuff that I was able to rip properly.

Reading about this, it appears to be part of a Japanese exclusive duology of mobile Dragon Ball RPGs, with this one (literally translating to "Dragon Ball RPG: Boy Arc") being released in 2013, adapting from the Emperor Pilaf saga to the King Piccolo saga.
It appears that there was a predecessor, simply called Dragon Ball RPG, released in 2008, adapting from the Saiyan saga to the Kid Buu saga, with an updated version, Super Dragon Ball RPG, being released in 2010.

what is that???? so cute

I swear i never heard of this before,but as someone who always loved the first half of Dragon Ball it puts a smile on my face