コミックフラッパー
A related series with a new protagonist, , was illustrated by manhwa artist Shin Yong-Gwan. It was published by Media Factory's magazine "Comic Flapper" and between December 22, 2006 and November 21, 2009, six volumes were published in Japan. Two volumes of the series were published in English by Digital Manga Publishing on December 16, 2009 and May 10, 2010.