Kimiyo Tazu Hoshi, a brilliant but overly-driven scientist, is the supervising
astronomer at an observatory in Japan during
Crisis on Infinite Earths. The
Monitor decides that he needs additional forces to turn the war against the
Anti-Monitor in his favor. To this end, he sends a devastating beam of energy which strikes Hoshi, leaving massive destruction in its wake. Granted power over light, Hoshi is assigned by the Monitor to guard one of the vibrational forks needed to save Earth. Doctor Light has joined the
Justice League a few times over the years, most notably as a member of
Justice League Europe during the latter half of its incarnation. Kimiyo Hoshi appeared in costume in
52 Week 35, alongside various other heroes. All are assisting the injured victims of Lex Luthor, who had deactivated the powers he had given to select recipients. She is also shown in
52 Week 50, in the climactic battle of World War III. Dr. Light appears in
World War III: United We Stand, the fourth issue of the
World War III mini-series that coincided with
52 Week 50. She is one of the first wave of heroes who confront (and are taken down by)
Black Adam. He grasps her neck with such force that she instantly blacks out; he throws her aside.
Oracle invites Kimiyo to join the
Birds of Prey (issue #100), but she was not selected to take part in the first mission. She does, however, appear in
Birds of Prey #113 (January 2008), assisting Oracle by scanning the electromagnetic spectrum for any evidence that might lead her to the parties responsible for an influx of hi-tech weaponry being smuggled into Metropolis. She is unable to locate any such evidence. Doctor Light is only occasionally active in the superhero community because she is a single mother with two children: Imako, her daughter, and Yasu, her son. This is later revealed to have been orchestrated by Superman and
Icon so that the League and Cabinet could gain information on each other.
Hardware uses Arthur Light's powers to restore those of Kimiyo, allowing her to quickly defeat
Shadow Thief and
Starbreaker. Kimiyo has been confirmed to be a member of the newest incarnation of the Justice League. In the
Blackest Night crossover, Kimiyo and the remaining members of the League arrive at the
Hall of Justice after hearing of the
Black Lantern attacks taking place across the globe. Upon entering the Hall, Kimiyo senses the presence of her villainous counterpart, and separates from the group, believing this Black Lantern is hers alone to face. Kimiyo is attacked by Arthur Light, who has been resurrected as a Black Lantern. Although initially her powers seem to be ineffectual against Light, when he threatens the lives of her children, Kimiyo manages to generate a light strong enough to destroy him and his black ring. In the aftermath of the ordeal,
Vixen tells Kimiyo that she is taking a leave of absence from the team to recover from her injuries. She is approached by
Donna Troy, who joins the team alongside her friends
Cyborg,
Dick Grayson, and Starfire. With the costume given to her by Hardware destroyed, Kimiyo designs a new one, and then travels to Metropolis to recruit
Mon-El and
Guardian. Kimiyo briefly appears during the
War of the Supermen, where she and the rest of the JLA attempt to repel
General Zod's invasion. After just three issues together, the new JLA team loses most of its members, with Kimiyo temporarily leaving the team to be with her children. Back in Metropolis, Kimiyo helps
Supergirl rescue her friend
Lana Lang after her body is possessed by the
Insect Queen. A short time later, Kimiyo and
Gangbuster investigate an object that crashes into a Metropolis park and leaves a massive crystallized crater in its center. While searching the crater, the two heroes discover a
Bizarro-like creature resembling Supergirl. Before Kimiyo can call for help, the creature lashes out and attacks her. The Bizarro Supergirl takes Kimiyo and her associates hostage, but is ultimately defeated in battle by the real Supergirl. It is revealed that the Bizarro Supergirl is a refugee fron
Bizarro World, and was sent to Earth by her cousin after their planet was attacked by a being known as the Godship. Kimiyo attempts to take the Bizarro Supergirl to S.T.A.R. Labs, only to be knocked unconscious by Supergirl, who then absconds with her doppelganger and her ship, hoping to stop the Godship and save Bizarro World. Despite resigning from active duty, Doctor Light appears as one of the numerous heroes assembled at
Washington, D.C. to break an energy dome trapping the Justice League and the
Crime Syndicate of America within the city, as well as a member of the JLA's reserve roster during the team's battle against
Eclipso. She also assists the League (as well as several other teams) during a battle against the
Secret Six, where she is gunned down by
Deadshot.
DC Rebirth Kimiyo appears in the
Rebirth storyline
Heroes in Crisis and is among many superheroes that are interviewed in the Sanctuary therapy center. Furthermore, she and Arthur Light were formerly married, during which they had three children: Tommy, Emma, and Sakura. ==Powers and abilities==