Check Out the Arena and Optional Dungeons
After completing the first two chapters in the main story of Tokyo Mirage Sessions FE Encore, you’ll unlock the optional dungeons in Bloom Palace, as well as the Urahara Arena in Harajuku. Both of these facilities can be very useful if you take the time to get familiar with them.
The optional dungeons in the Bloom Palace are great for level grinding, and you can even get valuable items there such as skill tomes, which let you level up quickly and attain weapon mastery at a faster pace. You can also pick up valuable treasures and sell them for more money.
The Arena is where your combat prowess will be tested, as you have to survive against waves of enemies with a fixed party. Winning battles here will reward you with Arena Coins, which can be exchanged for a variety of prizes, including Master Seals.
One very important thing to note here is that if your party happens to get wiped out in the Arena or the dungeons, you get an instant Game Over, and you’ll have to start from your last save. So make sure you save your game often.