What kind of title is this?: Manga.
Where can I read it?: Reading links are listed for K MANGA, Kodansha USA. Check availability in your region.

Synopsis

About Tank Chair

Shizuka takes on the most dangerous of assassin jobs, but she's not the one doing the killing. Rather, it's her brother, Nagi, a strong assassin who took a bullet to protect his sister, leaving him in a comatose state and having to use a wheelchair. However, Shizuka has figured out the key to waking her brother up: he must be faced with killing intent! Thus begins a violent journey of recovery, battling the most dangerous foes! (Source: Kodansha USA)

Action Sci-Fi