Early Single Box is the first box set compilation from J-pop idol group Morning Musume, and was released December 15, 2004. It contains their first eight singles in their entirety, each on a separate disc with an additional bonus track each. It also includes a ninth disc with fifteen instrumentals of some songs from their first three albums.

Although the original versions of the first six singles were pressed on 8 cm CDs, all of the ones included in the Early Single Box were 12 cm CDs.

All eight of the new versions of the singles were later reissued separately. The instrumental album is still exclusive to the box set.

...
Wikipedia