Original Soundtrack. // Source: Amazon.co.jp.
On the left is the cover that the sountrack was originally advertised with, on the right is the cover that actually ended up being printed on the disc. Neither cover is really anything to write home about, especially since the artwork has been used before. But I'm including both on this page for the sake of completeness, anyway.

Image Cross-Reference: Frontier Works Series IV collectible cards.

Original Soundtrack 2. // Source: scanned by me.
Blugh, more recycled artwork. I'm really surprised that Kyou Kara Maou can keep getting away with not having any original artwork on their main soundtrack covers!

Image Cross-Reference: Daikenkyuu 2 artbook cover, and Newtype Romance Spring 2007.

Source: scanned by tenshihimeayaka, arachne13, Animekitty421, and me.

Image Cross-Reference: Animedia February 2006, Newtype Romance Winter 2008, Minna no Uta Album (below), Radio CD advertisement, and the Daikenkyuu artbook cover.

Source: scanned by sophiehatter and Animekitty421.

Image Cross-Reference: Newtype Romance Winter 2008. Additional postcard references: Individual character albums (above) and Ura-Ma DX.

"Hateshinaku Tooi Sora ni". // Source: CDJapan.co.jp.
Contains the Kyoh Kara Maoh! opening theme, "Hateshinaku Tooi Sora Ni," and the first ending theme, "Sutekina Shiawase," both by The Stand Up.

"Arigatou" by BONZ. // Source: Amazon.co.jp.
The second Kyoh Kara Maoh! ending theme. Sorry about the small size of this image scan.