To level up quickly, focus on completing substories, Dondoko Island activities, and Sujimon Battles. The 'Hawaii Dungeon' and 'Yokohama Underground' offer excellent experience and rare materials. For money, Dondoko Island is your best bet once it's developed. Selling high-value items found in dungeons or earned from mini-games also helps. equip accessories that boost EXP or money gain when grinding.
