Relations for Natural ~Mi mo Kokoro mo~

 Natural ~Mi mo Kokoro mo~   1998-02-06 ja  Natural 2 -DUO-   2000-05-26 ja Same series  Natural Another One 2nd ...   2005-10-28 ja  Natural Another One   2003-09-26 ja Sequel  Natural Zero+ ~Hajimari ...   2000-12-22 ja Same series Same series  Natural Petit   2000-03-22 ja Fandisc