This is the first group album from the BIG idol project "B-PROJECT," brought to you by general producer Takanori Nishikawa and planning/original creator Chiyomaru Shikura! It contains songs that have colored the anime, new songs commemorating the 10th anniversary, and even new-song group versions included only on this CD! Comes with a bonus alternate jacket featuring a message ("Echoes of Us": MooNs ver.).