Template:Infobox Item Happy gem are items used for training happy cards and unlocking happy card side stories. To train a 3☆ card, 100 happy gems are needed. To train a 4☆ card, 200 happy gems are needed. To unlock the second side story of a 3☆ card, 600 happy gems are needed. To unlock the second side story of a 4☆ card, 1200 happy gems are needed.