12 years before the Embryo Incident, Hinata was kidnapped by the Takamagahara Group and brought to the Wadatsumi Research Facility. Since Hinata had the aptitude to be the Embryo, countless terrible experiments were performed on her. She was brought to the Gate of Sheol and told to speak to someone on the other side of it to get them to open it. When she failed, the scientists beat her. However, Ryouko Kagari put a stop to it and introduced her son, the original Touya Kagari, to Hinata in the hopes that they would become friends, which succeeded. Playing with Touya was Hinata's only happiness. One day, Touya tried to help Hinata escape from the Wadatsumi Research Facility. However, he had to use his Drive to protect her from their pursuers. The strain of it was too much for him. He died and Hinata was dragged back to the facility. As a result, Hinata shut down and stopped caring about anything. One day, she was brought back to the Gate, but this time there were a bunch of Mages and the Origin of the Grimoire. The Mages used the Origin of the Grimoire and a black tornado engulfed Hinata. She then heard a voice asking her what her wish was and she thought about seeing Touya again. This caused the Origin of the Grimoire to transform into a new Touya.
After the Wadatsumi Incident, Avenge took Hinata to the same orphanage as Yuki Himezuru and asked Yuki to act like an older sister to Hinata. There she once again met and befriended Touya. After Yuki became a doctor, she adopted Hinata as her younger sister.
Code: Embryo, Lost: Memories
Hinata first appeared waking up Touya in their classroom with her humming. Despite Touya's insistence that he could wait for Akira Kamewari by himself, she stayed, saying it was fun. Akira arrived and discussed the serial killer on the loose, which Hinata found scary. After Touya left for his part-time job, she and Akira discussed the fact that Touya felt the need to pay rent despite her and Yuki seeing him as family. Realizing it was almost 5, she said goodbye to Akira so she could get to the market before the sales ended.
That night, Es went to the Himezuru residence and was greeted at the door by Hinata, who couldn't contain her excitement about how cute she found Es. Es asked if Touya was there, but Hinata said he hadn't returned. Es said that she would wait outside for him, which scared Hinata, who claimed it was far too dangerous for a cute girl like Es to be staying outside that late, but Es said she could defeat anyone who attacked her. Hinata didn't understand her comment about being a soldier but invited Es inside anyway. 
When Touya arrived home late that night, she greeted him and told him that a guest had been waiting for over an hour to see him. Once Souichiro Unomaru and Mei Amanohokosaka arrived, Unomaru asked her for Earl Grey tea so she went to the store to buy some. After returning home, Unomaru and Mei left. She offered to prepare a bed for Es but Es insisted she would not sleep so she could guard Touya.
The next morning, Hinata told Touya that Es left before he woke up, saying her mission was complete. She then told him that Unomaru called to say that Touya's tests came out fine. On the way to school, the two met Akira. Despite Touya's protests, she told Akira about what happened last night. However, she didn't give a lot of context, causing Akira to get the wrong idea about him and Es. At school, she was happy about the “coincidence” of Es transferring into their class, only surprised that Es wasn't younger than them.  After homeroom, she spoke with Touya, Akira and Es, trying to explain the concept of friendship.
After school, Hinata found Es in the hallway, having heard from Yuki that Es would be living with them. Hinata was happy, saying they'd be like family and they went home. On the way home, Hinata told Touya and Es that Yuki would be coming home that night and wondered what to make for dinner. When Touya saw Akira and heard a Discover Call in that direction, he and Es took off and told Hinata to go shopping without them. After Akira was rescued, she met up with him, Touya and Es and Touya explained about Unions. That night, Yuki came home and jumped on Hinata excitedly, hugging her.  She then took a bath with Es. 
The next morning, she talked with Kuon Glamred Stroheim and learned that she would be staying with them. Hinata was happy that there would be more girls around. When Touya asked to speak with Kuon alone, she was initially disappointed but agreed and went off with Es. 
That night, she greeted Touya and Es as they came home, only to find them dirty and bruised. She demanded they take a bath and took Es with her first. 
After school the next day, she invited Akira to join them for dinner, which he accepted. She, Touya and Es then went shopping. After shopping, she told Es to pick out something she would like but Es didn't know so Hinata suggested they get pudding. At the pool the next day, she stayed out of the water because she couldn't swim. Touya eventually convinced her to go in with him.
Hinata met Touya and Es on the school roof during lunch and recalled that Yuki named her because her laugh was like the sun coming out.
While Touya and Es were assisting Kuon in tracking down the Ten Sages' wards, Hinata texted Touya to tell him they were having croquettes for dinner and to tell Es that she bought pudding. 
That night, Elise von Klagen came to the Himezuru Residence and tried to get Hinata to admit Kuon was being a burden but Hinata said it was more fun with her around. When Elise admitted she was in love with Kuon, Hinata let her stay the night. Later, she asked Touya if he was free tomorrow, but he said he just made plans to go shopping with Kuon and Elise. Hinata said it's fine but that “he” would be disappointed.
The next day, she went shopping with Akira but ran into Touya, Kuon and Elise. She said that Akira invited her and she tried to invite Touya the night before on her own, thinking it would be more fun with him, completely unaware of Akira's intentions. After splitting up with them, she heard the explosion from Kuon attacking Acht and ran over to Touya despite his and Akira's protests. After Acht left, she asked Touya if he was all right, which he confirmed. She told him that after they met up Akira suggested they should all hang out together. She asked Touya to be more careful since he kept getting in fights. She then told Touya that Akira left, texting her that something came up, and that she was worried about him since he seemed off.
The next day on the school roof, she discussed with Touya, Es and Kuon that Akira didn't show up and goes to ask the homeroom teacher about it. After school, Kuon asked Touya and Hinata how long they'd been friends with Akira and they told her about how their past. They then split up to look for Akira while Hinata went home.  That night, Acht arrived at the Himezuru residence and took Hinata hostage.
The next morning Hinata woke up fine, having been asleep through the entire event. She told Touya that Es was worried about him and stayed outside his room the entire night but he quickly left. Yuki found it strange that Touya was actually mad and asked Es if they had a fight. Seeing Es looking sad, Yuki realized she wanted to make up with him, but Es didn't know what that meant. Yuki explained that it meant she wanted Touya to like her again and Es asked how to do that, but Yuki said Es would have to figure it out on her own, calling Es an adorable little sister. Es said she was not part of their family, but Hinata said she still thought of Es as a little sister regardless, which Es did not understand. However, Es wanted to be part of their family, but Hinata and Yuki said she already was an important part of their lives. Es was horrified that she nearly made a terrible mistake and didn't want to lose her family so Hinata told her she wasn't going anywhere. Yuki told Es to tell Touya the same thing if she wanted him to like her again and Es thanked her and left. Hinata then wondered what happened and Yuki theorized that it was because both Touya and Es were awkward and there was a disconnect between their words and actions. Hinata asked what to do about it and Yuki said all one could do was like themselves.  Later Hinata went to Touya's room and asked to spend some time with him since she's worried about Akira and she spent some time knitting in his room. 
The next day at Shin Yokozaki University Hospital, Hinata came running to Yuki, having heard that Akira was in an accident. Yuki hugged Hinata, telling her that Akira would be fine and she needed to not look so sad.  Later, she went shopping but was kidnapped by Ripper, who knocked her unconscious, took her to the top of an abandoned building and chained her over the edge. Once Touya and Kuon arrived, Ripper cut the chain, leaving her to fall to her death but she was rescued by Es.  As Es was taking Hinata home, she was found by Sechs, who looked at Hinata and said the Embryo's peaceful world would soon end now that the power of the Black Beast has been released. Es told Sechs to leave and that she would protect Touya and Hinata, but Sechs merely found it interesting that a "will" had manifested in a doll and asked her what she most desired. However, before she could answer, Sechs disappeared. 
Later, Hinata woke up at the Himezuru residence, confused since she thought she was at the hospital. She decided to make dinner for everyone. She then heard the doorbell and wondered who's visiting her.  She opened the door to find Touya, Es and Mei. Touya smelled horrible so she told him to go and change. Es said that Hinata seemed to be herself and Hinata said it was a strange comment from Es. Es was confused about that but Hinata was just glad that she was in a good mood again. Mei asked Hinata if anything out of the ordinary happened but Hinata said she'd been sleeping until recently. Mei then asked her if Kuon returned and Hinata said she was upstairs. Hinata then realized she promised Kuon not to tell Mei about her return and begged Mei to pretend she didn't hear but Mei refused. Hinata was afraid that the two would start fighting but Es said it's okay because Mei and Kuon were friends, which took Mei aback. Once Touya, Kuon and Mei came down, Hinata offered them tea and Mei said how good it is, but Kuon got upset when Mei called it “cheap.” Hinata told Touya that she was going shopping and wanted to know if they wanted anything but Touya said they'd be leaving soon. Hinata said that everyone looked like they had things on their minds and she wanted to help but couldn't do anything, but the others assured her that she was fine like that. Es then asked her to get pudding for her, which Hinata happily accepted. Later, just as Mei complained about Hinata taking a long time to get back, she arrived with pudding. Touya told her that Akira had regained consciousness, which delighted her. Hinata said she wished she brought pudding for Akira, but when Touya said Akira can't move enough to eat it, Hinata said she'd spoon-feed him if necessary. Kuon said she's sure that would make Akira happy. Touya then told Hinata that they would be out late and she shouldn't wait up for them but she insisted she would. After everyone left, she heard the doorbell and went to answer it.  Hinata opened it to find Unomaru, who said he came to talk to her about Touya's past. He then convinced her to follow him to the Wadatsumi Research Facility to hear about it. Unomaru explained about his desire to make all of mankind happy by taking away free will but Hinata said she didn't understand. Unomaru then told Hinata that Touya wasn't human and that she was the one who created him. Unomaru started attacking Hinata, trying to force her to remember what she did and yelling at her for ruining his plans. Hinata passed out and he decided to plug her into the T-System. 
In the core of the T-System below the Wadatsumi Research Facility, Unomaru revealed that Hinata was actually Code: Embryo. Unomaru then forced Touya to use the Origin of the Grimoire to refine the Embryo. After Sechs killed Unomaru, Hinata had a strange dream where she remembered the Wadatsumi Incident and the Black Typhoon. She then saw someone who she thought was Touya and told him she's scared, but it was actually Sechs, who told her that her role was over and stabbed her with the Sword of Destruction: Kusanagi. Sechs said he sealed her soul so she could no longer perform random Phenomenon Interventions. In the real world, Sechs launched Kusanagi at Hinata, knocking her into the Boundary.
Inside the Boundary, Hinata called for Es. Es realized that Hinata had lost her body and Hinata apologized, saying she wouldn't be able to make dinner anymore. Es said she can no longer protect Touya but Hinata said that it's not true and she knew everything. Hinata told Es she could give her her “heart” and if she did, they might be able to save everyone. However, if they did, Es might never be able to return. Es said that her only wish was to protect Touya so she would accept Hinata's heart. Hinata then gave the Embryo to Es and Hinata revealed that Es's real name is Embryo Storage. Hinata apologized, but Es said she made the choice of her own free will. Hinata then told Es she must touch the Master Unit and if she did she would understand everything. Hinata asked Es to save Touya. Using the powers of the Embryo, Es restored Hinata's body and returned her to the Himezuru residence with no memories of being the Embryo.
One month after the Embryo incident, at the Himezuru residence, Hinata offered Mei some tea. Mei said she didn't stop by for tea, but Kuon pointed out the box she had. Mei said it's a gift she just happened to pick up and Hinata said it's fine for Mei to visit whenever she wanted and went to make tea for the rest of them. After making the tea, Hinata approached Touya, Kuon and Mei, agreeing with Kuon and Mei that Touya had changed for the better. Touya asked if she heard the whole conversation but Hinata said she was making tea. Hinata brought the sweets Mei brought and revealed that she knew Mei actually went to another town just to get them, much to Mei's embarrassment. Later, after Yuki arrived, Kuon said she needed to leave. Hinata was sad but Kuon said she would definitely visit. Kuon then left. 
10 days later, Ringo Akagi was at the Himezuru residence and tried Hinata's curry, praising her skill. Later, after Ringo left, Hinata called that the curry was ready, but Touya was sick of it after having eaten it for 10 days. 
At the Himezuru residence, Hinata came into Touya's room, asking if he wanted to come with her to visit Akira. Touya agrees and they went to the hospital. At the hospital after Touya and Akira had talked, Hinata came in, apologizing for being late since she had been talking to Yuki. Hinata accidentally revealed that she told Akira to try and cheer Touya up since he seemed depressed and that was the reason for the visit. Hinata and Akira told Touya he could talk to them about anything but Touya said it was something he had to solve on his own. He then received a phone call from Mei, so he said goodbye to the two.
Touya went to visit Akira again and was surprised to find Hinata was there. Hinata excitedly told him that Akira would begin his rehabilitation the next day. Akira noticed that Touya looked contented and Touya said he settled a lot of things. Hinata got jealous of their friendship between “bros.” Touya wanted to tell them about his decision, but he suddenly heard a Discover Call coming from the school. Touya left, saying he would see them tomorrow. 
One month later, Touya woke up after school to Hinata's humming. Mei arrived and apologized for being late. Touya said he needed to get going and Hinata wished him luck with his new job, saying it's a shame Maha Raja closed so suddenly. Touya tried to say that it wasn't a job but decided it's close enough. Hinata then told Mei that she received mail from Kuon, saying that she made it back to Ishana safely and to tell Mei that she would keep her promise on the hone of the true Ten Sages. It also said that, due to Elise's insistence, they would be back in Japan soon. Mei said that meant they'd just have to work even harder. Touya said that he would be out late and Hinata should eat dinner without him, but Hinata insisted that she would wait for him since meals are more fun with other people. Mei then told Touya to move out and not to fall behind.
The next morning, Touya and Hinata greeted Yuki in the hospital and Hinata asked about Akira's condition. Yuki said he'd started walking and was slowly getting better and it was okay for them to visit him. Yuki told them that since Akira was scheduled for rehab he was probably in the garden. After finding Akira, Hinata said she brought some pudding, saying that pudding is happiness. Akira asked if Hinata was going to feed him and she said of course. Akira said it's a bit embarrassing but Hinata had no idea why. 
- XBlaze Lost: Memories, Azure Main Memory 01
- XBlaze Code: Embryo, Episode 1
- XBlaze Lost: Memories, Azure Main Memory 02
- XBlaze Code: Embryo, Episode 2
- XBlaze Code: Embryo, Episode 3
- XBlaze Code: Embryo, Episode 4
- XBlaze Code: Embryo, Episode 5
- XBlaze Code: Embryo, Es & Hinata Route Episode 6
- XBlaze Lost: Memories, Azure Main Memory 03
- XBlaze Code: Embryo, Es & Hinata Route Episode 7
- XBlaze Lost: Memories, Green Stone Sub Memory 03
- XBlaze Code: Embryo, Es & Hinata Route Episode 8
- XBlaze Lost: Memories, Azure Main Memory 04
- XBlaze Code: Embryo, Es & Hinata Route Episode 9
- XBlaze Code: Embryo, Es Route Episode 10
- XBlaze Lost: Memories, Azure Main Memory 04
- XBlaze Lost: Memories, Black Stone Sub Memory 01
- XBlaze Lost: Memories, Black Stone Sub Memory 02
- XBlaze Lost: Memories, Black Stone Sub Memory 03
- XBlaze Code: Embryo, Es Route Episode 12