Mariko Yashida was the gifted daughter to rather strict parents in Japan. Her discovery of her mutant abilities as well as her same-sex attraction earned her the rejection of her parents and she subsequently joined Professor Xavier's X-Men, working for his dream of mutant-human peace. At some point, Sunfire found herself in the company of a man calling himself the Timebroker. He explained to her that she had become unhinged from time as a chain of events had caused her realities as she knew it to change. New events in Sunfire's past caused her powers to manifested as uncontrollable atomic radiation. In order to return to her correct timeline, she would have to help repair other realities that caused the ripple effect that disrupted her reality or else return to her new, unfortunate alternate existence. When Sunfire joined the team after the Exiles lost their first member, Magnus, Morph aided Mariko in adjusting to the team's chaotic lifestyle by helping her see the lighter side of every situation. The two formed a close relationship and Morph began to develop stronger feelings for Sunfire outside of friendship. In time, Mariko would reveal to Morph that she was a lesbian and had hesitated to tell him because she had a hunch about how he felt for her and didn't want to hurt his feelings. Morph took the news amazingly well, reacting in a sensible manner and they would continue the best platonic relationship in the team.
On a mission to a timeline in which the Legacy Virus had mutated into a global techno-organic epidemic, Sunfire met and grew close to Mary Jane Watson who served as the Spider-Woman in the Avengers of that reality. Not much of a relationship could develop, however, as the team immediately left when the mission was complete, although they were forced to leave without their team leader, Blink.
Blink's replacement was a cruel version of Illyana Rasputina who antagonized all members of the team and attempted to flirt with Sunfire. On a visit to an alternate reality where all of Japan was destroyed by Moses Magnum and Namorita, Mariko not only came face to face with Illyana's desire for butchery she also discovered a deceased alternate-reality version of herself.
When the Exiles visited a reality where they would clash with a Captain America who had been transformed into the Nosferatu and killed Baron Blood to assume the title of Vampire King, Mariko was bitten by one of his Cursed Avengers and was rapidly changing into a Vampire. With the help of the current Union Jack, the Exiles were able to cure Mariko by slaying Captain America, thus severing the bloodline of her maker. Although Crichton aided the Exiles in preventing Sunfire from transforming into a Vampire, he had an ulterior motive for slaying Captain America. When Crichton and Captain America last met, Crichton revealed that he was also a Vampire and, with Captain America now dead, Crichton becamse the rightful heir to the mantle of Vampire King by way of his Great-Uncle, Baron Blood. At his moment of ascension, he was incinerated by a revitalized Sunfire. Just as the Exiles began teleporting to their next dimension, Crichton's slowly burning body had enough energy left to cast an incantation that caused the Exiles to be split apart into multiple smaller factions on different worlds in different times.
Nocturne and Sunfire teleported into the middle of nowhere without their teammates and quickly realized that they had returned to Earth-Legacy. After some time, it became evident that they would be stranded in the timeline indefinitely and Nocturne and Sunfire joined the Avengers in their efforts to cure the remaining infected population. The newly reunited Sunfire and Spider-Woman decided to make the most of this fortunate turn of events by spending as much time as they could together and continue their relationship. After Nocturne noticed that Sunfire and Spider-Woman were falling in love, she pulled Mariko aside to warn her to be careful. Eventually, as Nocturne had warned her, their unexpected visit to the planet would end and Mariko would have to leave behind someone that she loved. Nocturne advised Mariko to be realistic and not prolong her relationship with Mary. Four days later, Mary let loose that she overheard Nocturne and Mariko's conversation and, after some thought, was not too sure that Nocturne was wrong in her beliefs. Nonetheless, Sunfire refused to end the relationship and told Mary that their time together was the most important thing that had ever occurred. Together, Mary and Mariko decided to continue their relationship despite the drastic uncertainty of their lives. Unfortunately, after over two weeks of happiness, Mariko and Nocturne were suddenly whisked away to their next mission, leaving both women devastated.
The Exiles then visited a world where the Thing had been turned into a psychotic monster, Mimic had suffered severe injuries while battling the Thing when he was hit hard while not in steel form. He had hidden from his teammates the fact that he had been infected with a Brood egg on the last alternate reality he visited while separated from the team. With his Healing Factor under strain, working to repair his current injuries, the Brood egg was able to slowly take him over. Sunfire and her teammates were now forced to fight their most powerful member and their leader. While engaged in combat with Calvin, Mariko dodged an Optic Blast that was meant for her and it instead hit a building. The falling debris would have crushed a crowd of people if Sunfire hadn't intervened. However, because she had expended so much energy fighting Mimic, she was not able to disintegrate all of the crumbling building in time. Although she was able to save the lives of many, it would have to be at the sacrifice her own as Mariko Yashida was buried alive beneath the debris.
Several missions later, the team discovered the Timebroker to be false and that the deceased body of Mariko Yashida was being held in permanent stasis in a crystal palace. A devastated Morph decided he wanted Sunfire to be buried in the reality where the Legacy Virus took place, granting her lover Spider-Woman the chance to visit her grave.
Solar Flare: Sunfire had the ability to absorb sunlight, and convert it into superheated plasma which burst into flame on contact with the air.
- Plasma Blasts: She could use her plasma to fire beams of scorching heat or powerful bursts of solar fire.
- Flight: She could fly by surrounding herself with a corona of fire, and then pushing the flames downward in a tight jet of superheated gas, shooting her through the air like a missile.
- Heat signature sense: Sunfire could see heat, by shifting her range of vision from normal light to infrared light.
- Heat and radiation immunity: Sunfire was immune to extreme heat and radiation.
She could fly.
- 40 appearance(s) of Mariko Yashida (Earth-2109)
- 4 appearance(s) in handbook(s) of Mariko Yashida (Earth-2109)
- 1 minor appearance(s) of Mariko Yashida (Earth-2109)
- 1 mention(s) in handbook(s) of Mariko Yashida (Earth-2109)
- 41 image(s) of Mariko Yashida (Earth-2109)
- 2 quotation(s) by or about Mariko Yashida (Earth-2109)