ONE N' ONLY released their major debut CD! Contains a new song (title song), "Bittersweet" and "BOOM BASH," which is the theme song of their tour "||:ONE N'ONLY:||." This edition comes with a trading card randomly selected from 12 kinds (members' solo x 10 + group x 2). The picture patterns of the trading cards for the Type A, Type B and Regular Edition (First Press) are the same.