Resurrect a monster from any files in your computer
Train and strengthen its stats
Play with it at the park
Join various competitions
Higher its ranks
Go exploring near the town with your monster
Combine monsters and create a completely new monster
And more.
The built-in translation dictionary is not professional yet, but I think it is at least playable.
http://hirotaka2014.sakura.ne.jp/mh0406/game/bm.htm