To commemorate her 45th debut anniversary, a best-of album was released. It includes originals, self-covers, and newly recorded songs. 45 songs, carefully selected by Seiko-chan herself, are included. 4 CD set with lyric booklet. Played only once after purchase, so the item is in beautiful condition. Serial code is not included. All of them are must-have masterpieces, resulting in a wonderful 4-CD album.