It's not hard as impossible, but yes, you will have to grind to beat the game. But, if your characters are leveled enough and with good items, you won't have trouble, it's not one of those games that you can only beat bosses with a certain strategy
But yeah, be prepared to spend some time grinding...and going a lot into the item world to level up both your equipment and your characters
Though I found the grinding is more fun than in other games, specially because it's so unconventional. Plus, you can "force" the grinding, for example by throwing one enemy into another you can get a more powerful one, perfect to get lots of EXP if you kill him








