These two-volumes manga are the prototypes for the "'Wolf Guy Series" novels, especially for the first two novels volumes entitled "Ookami no Monshou" (狼の紋章) and "Ookami no Enka" (狼の怨歌).
The series has been readapted with a more violent and mature setting in 2007 by Yoshiaki Tabata and Yuuki Yugo. This new adaptation is known as Wolf Guy - Ookami no Monshou.

Unknown to the world aliens have begun to invade people's bodies. A young race car pilot named Toshio was won by a mysterious organization for a "test" for money. That test turned out to be a hellish training to become a Zombie Hunter. However, Toshio decided to return to a normal life but soon face the harsh reality of a Zombie Hunter. Surrounded by shallow figures and aliens Toshio accepts his new life as a Zombie Hunter ...

(mangaka never finished the story)

A high school student named Yu Komori is bitten by a radioactive spider, which gave him spider-like powers.