Marion Wing was born in the 21st Century of his world: A 'Modern Era of Spirits,' where the mere idea of them was kept to legend and folktales. His mother and father were both entirely normal humans, and their son was initially just the same. However, Marion was born with strange white hair and unnaturally bright cyan eyes. A trait credited to spirits being interested in the boy, who was born with the ability to see them.

His strange appearance frightened his parents. To his father, it was a sign that Marion was the son of another man. It was the reason that his father walked out on them before Marion was even three years old, leaving his mother to raise a son she did not want.
To his mother, his creepy looks were a sign that Marion was not even human. Granted, the young woman would have accepted any reason to abandon her burdensome son. When the topic of spirits began picking up attention, his mother determined that Marion was a spirit sent to curse her. She decided she could repent for her sinful early life by taking Marion to an active shrine and abandoning him.

Meanwhile, Marion was an exceptionally bright boy. At age five, he understood that the spirits he saw were not normal. He also understood why his mother thought he was a curse, that she hated him, and that he had made her life very difficult. So when he was left on the steps of an oceanside shrine, Marion made no attempt to follow his mother. He even promised never to tell anyone about her, and allowed his mother to escape him.

Fortunately, the shrine in question was not abandoned like Marion was. It was dedicated to the Kami of the Ocean, who was still worshiped by the nearby fishing village. Some of the elders found Marion in the morning, and they were mystified by how he could see the spirits they worshiped. They believed that Marion was the Ocean Kami themselves, and took him back to the village. There he adopted the name "Shiro," for his white hair, because he refused to give up his birth name. After all, he didn't want anyone to link him to his mother.

For three years, Shiro lived in the village as a Kami... but he was not actually a Kami. The real Ocean Kami was still attached to the shrine, and her power was fading. The villagers believed in their Kami, but only to lay blame on her. They blamed the Kami for every poor fishing season, every bad storm, every sinking ship... As a result, their Kami only had the ability to do terrible things with her spirit magic. She hoped that Shiro would change their opinion of her.

That never came to pass. Instead, the villagers began to blame Shiro. He was isolated from children his age due to his supposed status, and the adults only treated him well out of self-interest. When that good treatment turned to outrage and abuse, Shiro believed he deserved it. He was called 'The Curse of the Sea,' and it was believed that Shiro had come to destroy the village.

At age nine, the villagers finally had enough of him. They contacted a spirit hunter about the little Kami that had come to curse them. Spirit Hunters snuck in one night, took Shiro to the shrine, and murdered him. At least no one had the will to disrespect the child's body: He was left with a stab in the back, completely aware of how hated he was.

This was the shrine of the Ocean Kami. She was outraged to see what the villagers did to the poor boy, who did not actually possess the power they blamed him for. The Ocean Kami threw a fit, creating huge storms and killing fish with her evil powers.
However, no one connected the punishment with their crime. Instead, they believed that it was Shiro cursing them. They cursed him in return, blaming Shiro for every disaster that had ever befallen any of them and officially thinking of him as The Curse Kami.

Faith is miraculous. And sometimes, miracles are cruel.

In this case, the miracle was Shiro's revival. His spirit became a Kami, and his shrine became his own human body. Shiro woke up in his corpse, but was unable to feel pain from the stab or see the wound at all. He simply believed he had been lucky somehow.
This shocked the Ocean Kami. She could feel her own power fading and understood that Shiro was replacing her, but felt no ill will towards the child. Rather, she felt oddly maternal towards the young boy. She didn't want for him to know he had died, so lied to him. But she also urged him to flee from the village, before they found out he was still alive.

Shiro did not doubt the Ocean Kami. In fact, he immediately trusted the beautiful spirit woman before him. Shiro began calling her "Princess" because she was so beautiful, with the address eventually shortening to "Prinny."
Unknown to both of them, this nickname became Name Magic, and the new name became Prinny's shrine. Prinny led Shiro away from the shrine, but the entire time she expected to be chained to her physical shrine. She was surprised when she was able to leave the village behind. But Prinny never questioned it, and instead decided to make raising Shiro her top priority.

The two of them arrived at Asteria City, where they met "Tina the Tourism Kami." Tina's shrine was a tourism mascot for the town, and she had a lot of faith thanks to the children in Asteria. She allowed them to live in the attic of the tourism bureau. Initially, no one else in town could see Prinny... But Shiro spoke of her so confidently that even the adults began to believe that he really did have a beautiful older sister.

Thanks to Shiro's sincere love for his two new sisters, they both came to inhabit powerful name shrines. Tina and Prinny both became physical illusions, who got part-time jobs and started renting a real home for Shiro.

Though not conscious of name magic, they began calling him "Shi" and their family "The Yamato Family." Stories of "Shiro the Curse Kami" were beginning to filter into the modern city of Asteria, and they feared anyone making the connection. As much as possible, the girls wanted Shi to live a normal life. The now-sisters enrolled Shi in public school (because apparently it was illegal not to let him go to school or something,) and the three enjoyed a quiet, happy life.

It was happiness that did not last. Because despite trying to rename Shiro, his curse powers caught up to him. Not because anyone knew "Shi" was "Shiro," but because he himself still believed that he was a curse. Shi was a Kami, but his human body allowed him to create his own faith: And his own self-fulfilling prophecy.
It started small, but once it did begin it quickly snowballed. Broken mirrors turned to broken computers, lights flickering if he touched them, people getting sick if they sat with him... His school friends became wary, and even the adults began to wonder why Shi was plagued with tragedy. When spirit hunters wandered through Asteria, they recognized the now twelve year old boy as the one they had tried to kill years before.

This time, Shi was not killed. When Prinny and Tina realized the family was in danger, they packed a bag for Shi and told him to run. They promised to follow after him, but that they would throw the spirit hunters off his trail. He agreed and took off to a nearby forest.

Neither sister succeeded in coming after him.

After waiting for the entire night, Shi went back to check on his family. He found their home burnt to the ground, Tina's mascot self vandalized, and that all local spirits had been destroyed. He himself was discovered by some townspeople, and was fortunate enough that they were kind people. They were people who had adored Tina and Prinny, and adored Shi too. Even when they knew he was the Curse Kami Shiro, they could not hate him. They gave Shi money and supplies, then urged him to run away before anyone discovered him. When the twelve year old boy asked how he could repay them, he received a confusing answer:

"Just find a place where you can smile again."

Though confused by the request, Shi agreed. He left Asteria and began traveling on foot. Along the way, he continued to meet spirits and befriend them. With every town he stayed in, Shi made friends and created lasting name shrines. He also left a trail of destruction in his wake. Those who were kind to him suffered grave misfortunes, the places he lingered in were struck with natural disasters, and there was a clear media trail documenting terrible things that happened along his traveling path. The number of people who cursed Shi only grew, and with the stronger blame game came even stronger powers. It was a cycle that he could not escape.

As Shi was growing up, the world around him was also growing. And it was changing. Spirits and Kami were becoming mainstream again. Popular rumors had turned to televised sightings, which then turned to actual Kami appearing on television. By the time that Shi was fifteen years old, the idea of spirits was so mainstream that regular people could catch glimpses of them. Spirits appeared as brilliant orbs of light, which appeared in flickers to those who believed.

As this Era of Changing continued, humans blamed or praised Kami even more than this ever. It was this increase in faith that allowed Kami to appear more publicly, which started a positive cycle for their rising powers. This cycle also pushed spirit hunters to train themselves more, as they realized Kami and spirits were becoming more threatening. Finally, it also created a wave of popularity in the media.

Kami often appeared as superheroes. There were cartoons and tv shows produced about these supernatural beings, which could help or harm the world in whole. Shi longed to be one of the "good guys," but was burdened by all the proof that he was a villain. He decided to change his name again, this time to "Yoshiya Yamato," and become a "good guy." He wanted to redefine the story of Shiro, and his powers, by being a superhero.

At Yoshiya's current canon point, he is trying to be a hero. He lives alone and tries to fight crime at night, though clumsily so due to his powers. Even has he optimistically tries to change his self-image, he is afraid of attending school or going anywhere that he might hurt others. He continues to be his own self fulfilling prophecy, and accidentally causes more harm than good.