The origins of this game go back to sessions run by Takeshi Kikuchi (菊池たけし), serialized in RPG Magazine in 1991. Kikuchi developed rules to replicate a shonen manga style adventure such as Dragon Ball. He used a 2d6 system in which one of the values from 2 to 12 is designated as a critical hit value and another as a fumble value. These values are chosen randomly at the start of play.
7 is the most likely occurring value in a 2d6 roll and the number features prominently throughout the game. There are 7 attributes: sky 空, fire 炎, forest 森, sea 海, darkness 闇, ice 氷, and illusion 幻. The setting is a fantasy world called Lars Feria which is divided into 7 cultures. The ruins of ancient cultures are found throughout the two continents, the most famous of which are 7 forts.
Enterbrain published a V3 edition in 2002 and a fourth edition (called Mobius) in 2008. Fujimi Shobo published replays (dragon book series number 20) for the V3 edition.