A series of Sonorama Bunko books by Satoshi Rokudo, each volume with a different theme. - Title: Su no Reihousho (Water's Sacred Treasure Book) - Title: Kaze no Tenpoukan (Wind's Celestial Treasure Hall) - Title: Hi no Reihousho (Fire's Sacred Treasure Book) - Title: Chi no Shinpoosho (Earth's Divine Treasure Book) - Title: Tsuki no Reihousho (Moon's Sacred Treasure Book) etc. There is some yellowing, but it does not affect readability. Immediate purchase is welcome. Thank you very much for your interest.