AGE 0-3
- Mizuki was created and grown from the failed genome of another experiment (also named Mizuki, who was six at the time) and turned out to be a success.
- During this time, she was sent to the Aioen Orphanage along with the other Mizuki. The younger one would call the older one "Bibi", as she was too young to call her "Big Sis" like the rest of the orphanage would (We'll continue to call her Bibi).
- The place of her creation, Horadori Institute of Genetics, would occasionally take Bibi and Mizuki, where they'd perform horrific abuse in the form of experiments to test their strength, healing, and durability. To tell them apart, Bibi was called "Rat", and Mizuki was called "Rabbit".
- When Mizuki was three, the Institute was shut down when word of their inhumane experiments got out. Mizuki would go on to be adopted by Renju and Shoko Okiura, thus becoming Mizuki Okiura.

AGE 4-8
- Mizuki would go on to forget her time at both Horadori and Aioen, and wouldn't be told she was adopted for a very long time.
- While there may have been happy moments with her family in her early childhood, she doesn't remember them. Her earliest memory was when she was four and visited Bloom Park with her parents. It's such a vivid memory because it's the only time she can recall her parents were getting along and even laughing together.
- Renju became physically and emotionally distant as he focused more on his companies, though he'd still love her, and Mizuki was attached to him despite his neglect. Shoko, however, became abusive, hitting Mizuki when she cried and saying she wished the girl had never been born. Still, Mizuki loved her and wanted her attention.
- When Mizuki was eight, Renju and Shoko divorced, leading to the latter becoming Shoko Nadami. Since Renju claimed he was too busy with his work, Mizuki lived with Shoko, where the abuse became worse.
- One day, while drinking with her friend Kaname Date, Shoko ranted about Mizuki and how she wasn't like normal children, and revealed her abusive behavior to him. Upon hearing that, Date confronted Renju about it, who confirmed and even defended Shoko's position, even though he sympathized with Mizuki. When he rejected the notion of Mizuki living with him, as he had companies to run, Date claimed that the two of them were "shit parents".
- An agreement was reached between Renju and Date that the latter would take in Mizuki despite having no parenting skills nor any memory of what a childhood with them would even be like. Mizuki's new residence was a rundown studio apartment with barely any room for her. Renju remained Mizuki's legal guarian, while Date was considered Mizuki's roommate.

AGE 9-11
- Mizuki lived with Date and, while quiet at first, became more bold and comfortable in his presence, even though she couldn't stand many things about living with him. She had the chance to develop hobbies like breeding and raising clione and collecting Odoroki-man Chocolate stickers (though she grew out of that).
- On one of her birthdays during this time, Date gave her an Adorabbit doll. Mizuki dismissed it and called it ugly, but grew to love it over time. In the present day, she even has Adorabbit decal and stickers on her moped.
- When she was eleven, Mizuki had gotten beaten up by bullies, which prompted Date to teach her self-defense. This led to the two of them discovering Mizuki's super strength; she'd always had it, but she never used it since she never fought back with her parents, which taught her to just take abuse. Date taught her mental discipline and martial arts, and she would later go on to knock over a tree with a single kick. She never lives it down. Incidentally, the bullies ran away once Mizuki said she'd beat them up, only to pick on another kid, leading Mizuki to knocking out their front teeth.
- During the same year, Mizuki met Iris Sagan while meeting with her dad at one of his companies, Lemniscate. They'd bond over living with a single parent and being hanging out together. Iris would go on to introduce her to her other friends, and Mizuki took to them well. Those friends consisted of Ota Matsushida, Kizuna Chieda, and Amame Doi, who worked at her father's other company, Sunfish Pocket. They were all six years older or more (in Ota's case) than her, as she felt she never got along with kids her age.
- (Note: Lemniscate is an idol company while Sunfish Pocket is a maid cafe that has a mermaid theme.)
- It's assumed during this time that Mizuki also met Shoma Enda, a classmate of hers who would develop a crush on her.

AGE 12
- On November 1st, Mizuki got a message from Renju saying that he needed help and to meet him at Bloom Park's merry-go-round. At this point, the park was abandoned and restricted, and Mizuki, scared to go alone, asked Ota to come with her. The two went to the merry-go-round and found Shoko's corpse tied to one of the ride's horses with her left eyeball missing and an ice pick in her socket. Ota ran away while Mizuki, in shock, pulled the ice pick away from her mother. A noise startled her, and she hid in the center column of the merry-go-round. She would later be found by an investigation team that Date was part of.
- Mizuki stayed overnight in Central hospital with Date by her side. The doctors noted that she was physically fine, but the trauma left her with aphonia, rendering her unable to speak. In addition, it didn't look good for Mizuki as far as evidence goes, what with her being found with a bloody ice pick.
- Date brought her to his workplace, the police station, where he revealed that he was an ABIS (Advanced Brain Investigation Squad), which psynced into peoples' dreams to get clues that the person couldn't tell for whatever reason. There, Mizuki was psynced into by Date both to figure out what happened (since she couldn't say) and to try to cure her. While the former helped move the case along, Mizuki's aphonia persisted. She was brought back to the hospital.
- That night, she texted Hitomi Sagan, her school teacher and Iris's mother, and requested to be brought back home to Date's apartment. Hitomi did so, and there, she held Mizuki close the whole night. In the end, this was what cured her aphonia, and when she spoke, she cried. Not only had her mother been gruesomely murdered, but her father was missing as well, and was a prime suspect in the case.
- A few days later, the case came to a head. The psync machine had a hidden feature: if a psyncer stays in the dreamer for more than six minutes, their consciousness gets absorbed by the dreamer, while the latter, not being able to handle two consciousnesses, would push their own to the psyncer. Essentially, a body swap would occur. This happened with Date six years ago, and the person who psynced with him, Saito, wanted his body back and murdered those who were close to Date to rattle him. Saito had been in Shoko's body and, after being swapped with, Shoko committed suicide. Saito in Shoko's body met with Renju, swapped, and murdered him, leaving him (in Shoko's body) to be found by Mizuki. Now that he was in Renju's body, he met with an inmate named #89, or Falco, and swapped, leaving Renju's shell to die, as he'd been mortally injured earlier that day.
- (Still with me? It's a lot more complicated than that but I tried to keep it simple. Mizuki shows up later, just gotta set up the scene.)
- Saito was now in Falco, who was actually Date's original body. He revealed that he'd kidnapped Hitomi and Iris and planned to murder them as an extra fuck-you to Date (he had previous history with them). Saito, now in his own body, planned to follow through, but there was a wrench in his plan that he didn't foresee.
- Aiba is an AI that acts as Date's left eye. Trapped with Saito, Aiba sent a message to Mizuki, Ota, and Moma, a Yakuza boss, to help them all. Mizuki dropped in just as Saito was about to kill Iris, and though she got in a few good hits, Saito managed to gain the upper hand when he shot her in the leg. He promptly got his ass handed to him by Date for that, though he managed to escape to the upper floor, where Hitomi was being held.
- Saito nearly killed Hitomi, but Aiba, still in his eye, detonated, blowing up Saito's head along with herself.
- In the months that followed, Date officially adopted Mizuki, which made her take on the name Mizuki Date.
- With Renju gone, Mizuki inherited both Lemniscate and Sunfish Pocket from him, making her a very young CEO of both companies.
- Aiba's body was reconstructed as well, and she reunited with Date.
- On February 10th, Iris invited Mizuki to a quiz show. There, the lights cut out for a moment, and when they cut back on, the corpse of a CEO named Jin Furue was on the floor in front of them, perfectly cut in half. Moments later, as the police were trying to gather evidence, it burst into flames.
- The case, dubbed the Half Body Case, led Mizuki to an underground cathedral along with Date, ABIS agent Ryuki, Gen (a friend of Amame's) and Lien (new friend to the group who instantly fell for Kizuna) as they tried to find Kizuna, who the culprit, a man who called himself Tearer, kidnapped. There, they found Kizuna strapped to a chair with thermite bombs. After a failed ultimatum, Tearer made the bombs go off, resulting in Kizuna being permanently paralyzed from the waist down, Date to go missing, and Mizuki to lose her left eye.

AGE 13-17
- In Date's absence, both his and Mizuki's friends take on the responsibility of raising her. It's unknown if Aiba was partnered up with her during this time or if they joined up once Mizuki turned 18.
- Mizuki excelled in all of her classes, though she would start slacking in the last year or so since she had nothing else to really do. She never stopped looking for Date or thinking he was still alive. She stayed in the studio apartment even though she could easily move out, though she did burn all of Date's porno mags.

AGE 18
- Mizuki was hired by ABIS and officially had Aiba as her partner.
- She was only an agent for a few weeks when she got her first big break. On February 10th, exactly six years since the right half of Jin's body found and burned, the other half was discovered to be fresh, as if it had continued living until a few hours prior. At her own insistence, thinking that this could help her find Date, Mizuki took on the case.
- Just before she found the body, she was shot at by a figure in a cloak. Though Mizuki retaliated, the figure escaped.
- She found Ryuki drunk out of his mind and psyncs with him to find more details about the HB Case. From that, she learned that the name Tearer gave himself is "Dahlia Boat", though she doesn't get far with that information.
- The next day, Mizuki reinvestigated the scene where the second half of the body was found and, with Aiba's help, discovered that the body was carried with a one-wheeled robot. Knowing that her friend Shoma built a robot with the same schematics, Mizuki tried to find him. Though she failed, she did find out from Jin's nurse that he had suffered from a visceral disease and that he looked different from his public photos.
- Acting on a tip from Gen, Mizuki went to the rebuilt Horadori Research Institute, though she didn't have any memory of the place. She was attacked by Horadori's security, but the cloaked woman who had attacked her earlier dropped in and helped her defeat them. The woman informed her that she was looking into Horadori and the experiments they carried out, wanting revenge on the institution. After the security was defeated, Kizuna met them, having been leaving the place.
- To get answers, Mizuki psynced with Kizuna. Thanks to that, Mizuki learned that not only did Kizuna's father, who owned the Aioen orphanage, know about the inhumane experiments that Horadori and its founder, Chikara, carried out, but that Mizuki herself had been a test subject and was adopted by Renju and Shoko. The news rattled her.