Book 1

Jun 1, 2004
Japanese
Paperback (466 pages)

Book 2

Apr 9, 2010
Japanese
Paperback (343 pages)

Book 3

サウダージ[Saudāji]

by Ryosuke Kakine
Aug 3, 2007
Japanese
Paperback (439 pages)

Book 4

Jan 10, 2013
Japanese
Kindle (370 pages)