Miho is a man who has built himself from the ground up. He was born into extreme poverty and abuse, and overcame every challenge that was thrown at him. Putting himself through college was a trial, but his keen intelligence was so sharp that he managed to get a full ride excluding room and board for a master's in finance. It was as he was settling into a career as a stockbroker, that he become aware that his little brother, Taro was being raised by their shitty parents. He swooped in, offered his parents a lump sum of money via an airtight contract, to sign custody of Taro over to him.

As a legal guardian, Miho does his best to raise Taro without strife, but he's impatient and refuses to do any research into child-rearing. He becomes increasingly more abusive himself as Taro grows up, gradually escalating to fist-fights by the time he's a teenager. While Miho undoubtedly loves Taro, he does not like him, and it shows in the disdainful way he treats him.

• What Miho dreads the most, aside from losing people he loves, is the loss of status and money that gives him a buffer between him and the rest of the world.
• Had Miho not become a stockbroker, he would have instead become an architect. Not only does he have skill with art, but his mind is uniquely equipped for the mathematics needed.
• Miho's favorite season is Winter. He enjoys how crisp, cold, and peaceful the world becomes, but blatantly dislikes the holidays that come with it.
• The quickest way to Miho's shit list is having an association with his baby brother. Taro's lack of responsibility and hard work annoy Miho more than anything else. He built himself from the ground up, but his brother is content to laze around and mooch on Miho.
• Miho is cold and methodical when it comes to murder. He's made an art out of it, and he kills for the enjoyment of it, rather than the power plays being made.
• Although Miho has had sexual partners before, he has never had a romantic partner before Heli! She's his first and last one. There is no one that Miho loves or adores as much as her.

Miho was the light of his mother Emica Chino's life despite initially having been an unexpected and unwanted pregnancy. When the nurse lay Miho in Emica's arms for the first time, she gazed down at her newborn baby and, to her relief, saw nothing of the father. It was love at first sight, the stars having been weaved in the sky for her baby alone. Emica determined that Miho would want for nothing in life and went on to work three strenuous jobs to ensure it.

Though the efforts of Emica's work kept Miho fed and watered, he was often left alone at home when he was old enough to no longer need childcare services. With three jobs to contend with, Emica rarely had a moment to spare for Miho and instead took to writing and pinning notes around their home. They ranged from affirmations of love to directions for meals as well as reminders to do chores. Miho responded to each of them with messages of his own, his handwriting sloppy but improving as time passed.

On the rare chance when Emica had free time, she and Miho would dress in their fanciest clothes and make an outing of the day. They visited various educational hubs including museuems and zoos, but often simply went out to eat or played at the park. Miho's most precious memories are of days like this where quality time and bonding are the foremost thought of the day. They rival even the holidays when Emica would save up all year for a pricey quality toy that Miho picked out on his birthday.

Two days before Christmas, Emica is struck by a truck on the freeway. The driver had fallen asleep at the wheel and she died instantly in the resulting flame and wreckage. Miho was devastated when told by his newfound caseworker and was even moreso upset when he was placed with his biological father in the ensuing days. It quickly became obvious that Eito "Pop" Sakurai and his wife cared little for children. They spend most of their days drinking or gambling, self-obsessed and with violent tempers Miho was fast to avoid.

Miho survives his new family's abuse, and it comes as a surprise to no one when he abandons them both at eighteen. He's homeless for a while, scrounging to earn what he can to survive. Taking out an obscene amount of debt in student loans, Miho throws himself into his work at a prestigious college where he's earned some student aid funds to attend. He works hard, and builds himself a life in finance. He becomes a stock broker when he graduates, and his keen mind lends itself to his career, where he makes more money than he knows what to do with. He invests in it, and makes more money.

At the tender age of nineteen, Miho becomes a serial killer. He takes his pent-up frustrations out on people that won't be missed, and finds increasingly creative ways to dispose of the bodies. By the time he's halfway through college, someone finds out about his extracurricular activities. Instead of turning him into the police, the man makes a deal with Miho. Kill his enemy and he won't turn Miho in. Miho has no choice but to agree. He kills a series of people as he grows closer to the man, careful to discover where's he'd his the information on Miho. When he discovers it, he kills the man and wipes his drives. Only, he's got a taste for murder now, and after extensive research, he offers himself on the dark web as a killer for hire. He rises through the ranks in both fields of career, and ends up with more money than he could ever use.

The day Miho learns of Taro's existance, it feels like his life has come to a standstill. He angonizes over whether he should involve himself or not, but having lived through all the terrible abuse his parents put him through, he makes the first and only real sympathetic decision in his life. For a lump-sum payment, he buys Taro's custody from his parents and takes to raising the kid himself. He's not a good guardian, but he's better than them. Nearly a year after, he kills his parents to avoid new burdens from developing in his life.