Atelier Rorona: The Alchemist of Arland

You will unlock this trophy when Rorona reaches Lv. 50. The requirements for the Adventurer Ending requires both Rorona and Cordelia to reach Lv. 50, so if you followed the walkthrough and my suggestion in the Road Map, you'll earn this naturally.

Remember time doesn't pass once you're in an area; days only go by if you travel to a new area. That said, make sure you defeat all the enemies in an area before leaving.

A good place to grind is in the last "dungeon" you unlock as you progress the game, called Orthogalaxian. Before you begin your grind, bring a few Windrider items before you head to the dungeon. Windrider's allow you to automatically return to the workshop, so the amount of days it takes to return will always equal to one day. You can find the recipe for Windrider as a treasure in Lost City, so refer to the Krystal109's Item Guide if for some reason you haven't done so already.

Level 7 of Orthrogalaxian has 12 Bunny Puni's that you can fight. Each defeated Bunny Puni will net you 400 Exp. Simply clean out the area, return to the workshop via the use of a Windrider, and repeat. For efficiency, register the Windrider for Wholesale at Pamela's Shop.