Shiriusu no Kizuato is a four-volume (each volume consisting of 6-8 parts)
manga by
Shinichiroh Takada, and first appeared in
Shonen Ace, the "manga telephone book."
The story follows Takeru Tachibana and his sister Sayoko, whose parents were killed during a bombing on their home town when Takeru was 10. Sayoko, overcome with grief, sells her brain to the Albion corperation to pay for an operation for her brother.
The brain is placed within a robotic body, which essentially eliminates the majority of her past memories. Brains in this situation are made agressive and forced to fight in a highly illegal dogfighting circuit, which few survive. Sayoko, however, endures for 5 years and eventually attains the rank of 'Sirius,' the champion of the league.
For some reason, Sayoko is able to retain her personality, and the tale begins when Takeru helps her to escape from Albion, who ruthlessly persue their stolen property. Before long it is learnt that Sayoko's brain is swelling, and she has a mere 7 days to live.
The manga is unlikely to be released outside of Japan, ever. There are, however, unauthorized fan translations availible, which do a fairly respectable job. Mr. Takada doesn't seem to mind that these subs exist, so if you enjoy his work, you really should leave him a message at http://na.sakura.ne.jp/~byakuya/takada/index.html, a site he shares with Sakura Wars creator Byakuya Shobo. His English isn't too good, but fear not, a pet monkey named Asvin helps him with translations.
Two English renditions of the title exist. The first is Sirius Scars, which is used in the fansubs. Takada's preferred title is Cicatrice of the Sirius, which basically means the same thing.