Lillia and Treize (リリアとトレイズ Riria to Toreizu?) is a Japanese light novel adventure series by Keiichi Sigsawa, with illustrations by Kohaku Kuroboshi starring the children of the characters from Allison. There are six light novels in the series, published by MediaWorks under their Dengeki Bunko label. The first novel was released on March 10, 2005, and the last novel was published on April 10, 2007; there are three stories in the six volumes, with each story taking up two volumes. The series will be followed by Meg and Seron. A manga adaptation by Hiroki Haruse started serialization in the shōjo manga magazine Comic Sylph on December 9, 2006, also published by MediaWorks. An anime adaptation aired between April and October 2008 based on both the Allison and Lillia and Treize novels, known as Allison & Lillia.
Lillia and Treize began as a series of light novels written by Keiichi Sigsawa and drawn by Kouhaku Kuroboshi. The novels are published by MediaWorks under their Dengeki Bunko publishing label. There are six novels which encompass three stories split between two volumes each. The first novel was released on March 10, 2005, and the final novel was published on April 10, 2007. The series will be followed by Meg and Seron. The light novels have sold over 1.1 million copies.
A manga adaptation started serialization in the Japanese shōjo manga magazine Comic Sylph on December 9, 2006, published by MediaWorks. The manga takes its story from the light novels that preceded it, and is illustrated by Hiroki Haruse. The first bound volume was published by ASCII Media Works on April 26, 2008 under their Dengeki Comics label.