Hello everyone!
Today we're going to be talking about a character who has sadly been left out to the wolves in Star Rail, but that is still liked by many, Himeko! As a side note, this is also the first of these that I'm not doing directly on the Star Rail sub, instead doing it on the new community I've created specifically to discuss the lore of the Honkai series, HonkaiLore! But anyway, let's get right into this!
Himeko's splash art
First of all, disclaimer:
The Honkai: Star Rail characters and Honkai Impact 3rd characters who have the same name and similar appearances, except for Welt Yang, are NOT the same person, but instead you may think of them as something akin of parallel versions of each other! I go into detail about this and how the Honkai universe works here! Also, spoilers for Honkai Impact 3rd ahead, be warned!
Now let's get started!

Star Rail's Himeko

To summarize a bit about Himeko in Star Rail, we know her as the "leader" of the Astral Express gang. As a young woman, she found the Express when it became stranded in her world, and decided to fix it up so it could once again travel through worlds. Once she did, she boarded it and since then has been travelling around the universe. Along the way, she's met many companions, starting with Welt and "his blond friend", up to the current crew with the Trailblazer being the newest member aboard.
Though Star Rail has not yet given us much else in terms of her story, we'll now take a look at what her story is in Honkai Impact 3rd, and how this Himeko, Star Rail's Himeko, is important even outside of her own game.

Honkai Impact's Himeko

Himeko Murata, born on June 11th, 1987, is the captain of a battleship known as the Hyperion, as well as the leader of Schicksal's Valkyrie Squad V. In the game, she is a mentor to the main characters, much like her role in Star Rail towards the rest of the crew. She's also their teacher at St. Freya High School.
Himeko's base battlesuit, Battle Storm
However, before she became all these things, she went through a lot in her life.

Himeko's early life and Ryusuke

She was born to her father, Ryusuke Murata, and an unnamed mother. Her mother had a chronic disease, and spent all her time in a hospital. The doctors always requested that Ryusuke stay by her side, in case her condition would worsen, and in any case, to have someone close to her by her side. But Ryusuke would always leave.
Himeko as a child and her mother
You see, Ryusuke worked for Schicksal as the leader of a research facility, specifically the one in charge of a satellite, known as the 4th Divine Key. This was a satellite built by the Previous Era, a civilization from 50,000 years in the past, and it was a tool that would repair the world if and when that civilization was wiped out by the force known as the Honkai. 50,000 years later, it had completed its task and now floated around the Earth without a purpose, enticing Ryusuke to join the team. He had become obsessed with the prospect of alien life and its discovery through space exploration, and believed that his research would change the course of human civilization forever.
Though these may have seemed like selfish and impossible dreams (and selfish they most definitely were), the truth is that Ryusuke would indeed come across alien life. More than that, he would befriend it. But instead of finding it, he was found by it himself. One night, after one of his projects were cancelled for lack of credibility, Ryusuke went home in a rage, especially as this was the same day he received a notice from the hospital, notifying him of his wife's death. At the moment that he decided he would not let anyone or anything get in his way, someone, or more specifically something, approached him.
Ryusuke receives a letter from the hospital, and is watched by something
This little furball is known as Pepper Mint. He belongs to an alien race known as the Sugars, a race that travels from planet to planet, forming their civilization in a sort of "pocket dimension", a world of their own where they are never interrupted. They normally do not interact with humans, as they feel as though if they are discovered they must leave the current planet and move on to another one, but Pepper Mint decided to attempt to meet a human to become his "host". This is because the Sugars have an ability to become monsters, and lend this power to a host, and Pepper Mint had heard the story of Sugar Molass, another of his race who had traveled to Earth and found her host around this area.
Pepper Mint, after coming into contact with Ryusuke, informed him of another alien race, known only as the Sky People. This was a dangerous race, unlike the Sugars, who travelled across different worlds to find places that had high amounts of Honkai energy. They would then take over said places, take all the Honkai energy to feed their own devices while also replacing all living things with their own devices. Ryusuke made it part of his mission to stop the Sky People, perhaps in an attempt to justify the intensity of his research to himself.
Later, in 2005, Himeko had enrolled into the California Institute of Technology. She was studying Space Engineering, following in her father's footsteps, while also having become keen on following alien sightings and rumors of the sort. During her class under teacher Welt Yang, she received a notification for an alien sighting in New Mexico.
Himeko receives a notification for a new alien sighting
Welt Yang, as you may know, was not just any ordinary teacher. He was the sovereign of the group known as Anti-Entropy, as well as the Herrscher of Reason, a super powerful being. After becoming friends with Himeko accidentally, he saw this photo and immediately recognized it. It was not an alien, but instead the Arahato, a mech developed by Anti-Entropy. Of course, he couldn't tell Himeko this, as Anti-Entropy's actions, and the Arahato, were top secret. In order to protect the secret without allowing Anti-Entropy to hurt Himeko in any way, Welt decides to board the same plane as her, and they go to New Mexico.
Here, Welt and Anti-Entropy do their best to cover up the Arahato's existence, eventually finding a way to fool Himeko by plastering up a movie poster for the upcoming Arahato movie (in a rush, the word "coming" was mispelled), which upset her as an explanation but she believed it and left.
The Arahato movie poster
All the while, Ryusuke Murata had his own plans. He had contacted Anti-Entropy, warning them that Schicksal was to use the 4th Divine Key and its immense power to attack them directly. He had requested that they give him asylum in exchange for information on how to stop this attack, to which the Anti-Entropy scientists, Tesla and Einstein, agreed.
After meeting, they discuss the intel that Ryusuke had for them. He had brought a device for unlocking the 4th Key, as well as a document detailing its uses. Einstein shared her worries, as she had not found any information that hinted at the 4th Key even having any use as a weapon, but they took Ryusuke's gifts anyway, as he went to visit his daughter.
Ryusuke meets with Tesla and Einstein
Upon arriving to find Himeko and Welt talking, Welt feels a strong presence coming from Ryusuke. Though he didn't know it at the time, this was the presence of the Sugars' monster form. He decided to look into it immediately, even though Ryusuke didn't seem highly suspicious.
Upon activating the device Ryusuke had given them, Einstein and Tesla found that the 4th Divine Key began releasing Honkai energy and creating a storm over Houston. As Ryusuke, who was spending some time with Himeko, received notification of this, he left in a hurry and met once again with the scientists, claiming that Otto, Schicksal's Overseer, had planted a trap in the device that would activate the Key if anyone attempted to stop it. After helping them break into the device's emergency shutdown, they are able to stop it, but the device's existence, and the fear of reactivating it in an attempt to break its code, leads to Tesla deciding to launch Anti-Entropy's special Anti-Honkai missiles, the Silver Bullet, against the 4th Divine Key to destroy it. Ryusuke, with a small and fast smirk, states that he knows how to find the key's exact location.
Ryusuke offers to help find the key's coordinates
Welt, having his suspicions about Ryusuke, decides to go to his house, where the two men are forced into an amicable conversation due to Himeko's presence. Eventually they are left alone, and Ryusuke introduces Welt to his alien friend, and his monstrous form.
Ryusuke takes Welt into the Sugars' world, where they learn more about the Sky People. This is in an attempt by Pepper Mint to form an alliance between humans and the Sugars in order to stop the Sky People, not just from taking Earth, but to stop their plans entirely. However, the rest of the Sugars race is opposed to this alliance, and decide that they will leave the planet as they have been found out by humans.
Pepper Mint explains some details of the Sky People
As they leave this world, they find that Himeko has been attacked by the Sky People. Taken into Anti-Entropy's care, they find that she has been infected by them, and Ryusuke decides to reveal his intel in full to help his daughter. It turns out that his plan was to give the scientists of Anti-Entropy the wrong coordinates to launch the Silver Bullet, instead having it hit the asteroid the Sky People were using to survey and attack Earth. After having Welt use his powers to destroy this asteroid, it seems Himeko's infection recedes and disappears.
However, Ryusuke is not done. He reveals to Welt that he had been investigating blueprints from the Previous Era, that detailed a project named Project Ark. He wished to create a spaceship that would be able to save a few humans and send them into space, in the meantime allowing the Sky People to take the Earth, or the Honkai to destroy it. Welt is obviously opposed to this, as a majority of humankind would perish as a result, but Ryusuke has become obsessed with the prospect of space exploration and breaking free from the limitations of the human race. He is even willing to sacrifice his daughter for this. In a fit of rage, he crushes Pepper Mint, killing him and taking his power for himself to battle Welt.
Ryusuke crushes Pepper Mint
Despite this monstrous power, Welt is able to defeat, and kill, Ryusuke. Himeko, completely unaware of any of this, or even her father's motivations, is later informed by Anti-Entropy that her father had indeed died. However, his actions, as well as his cause of death, are kept secret from her, being written off as some sort of accident. Himeko, however, is not so easily fooled, and has her suspicions that they may be covering something up. In the end, she decides to join Schicksal after finishing her PhD to find out what truly happened.

Himeko's life in Schicksal

Himeko was not someone with any special abilities. In fact, she had lower Honkai adaptability than most, she was taken in by a mentor, a woman by the name of Ragna Lothbrok. Ragna incentivized Himeko, believing that anyone can become a Valkyrie with enough effort, and Himeko was eventually able to become one, at the age of 19, considered late compared to the average person. In an effort to become stronger against the Honkai, Himeko received an artificial stigma, an implant given by Schicksal that enforced a person's capabilities, but, for Himeko who had low Honkai adapability, this stigma reduced her lifespan, slowly corroding her body.
Ragna Lothbrok, as seen in a stigma art
In 2010, the Valkyrie squad Himeko belonged to, with Ragna as its leader, was sent to subdue the Herrscher of the Void, who had reappeared 10 years after its initial awakening. Her entire squad was killed in front of her eyes during this mission, with Himeko herself being the only survivor. Shortly after, she decided to join St. Freya High School as a teacher, perhaps in an effort to not allow other Valkyries to end up like her squad.
In 2014, the Herrscher of Thunder manifested for the first time in the city of Nagazora, and Himeko was sent to subdue and stop her from destroying the city. Here, Kiana Kaslana, Bronya Zaychik and Mei Raiden had all met and were traveling together, attempting to survive in the midst of a large scale Honkai attack on the city. However, the reality was that the Herrscher of Thunder had manifested within Mei herself. Himeko, using the Scarlet Fusion battlesuit, was able to match up to, and subdue, the Herrscher of Thunder.
Himeko dons the Scarlet Fusion battlesuit
Following this, Himeko and the principal of St. Freya, Theresa, persuade the three girls into joining the school and becoming Valkyries of their own, with Himeko becoming their main teacher, and leader of their Valkyrie squad.

The Herrscher of the Void

It turned out that the Herrscher of the Void had actually manifested within Kiana, Himeko's "favorite" student due to how much she saw of herself in her. In 2016, this Herrscher once again was released into the world, prompted by a plan by Schicksal's own Otto Apocalypse. Himeko was given a serum, known as HSN-b46, by Fu Hua. This serum had been created by a man known as Dr. Magi, when asked by Kiana to create an antidote to Himeko's Honkai corrosion.
Kiana asks Dr. Magi to create Anti-Honkai serum for Himeko
Himeko was led by Fu Hua's powers to find the Vermillion Knight battlesuit, a prototype of the Godsbane series which held a gem with Honkai energy close to the level of a Herrscher. This, combined with Himeko asking Tesla for help to create an anti-Honkai weapon using the serum, known as the God-Slaying Spear, would ensure that she'd be able to defeat the Herrscher of the Void.

The Final Lesson

(You can see the following section for yourself [here](https://www.youtube.com/watch?v=8dmvNGxYPCU)!)
With serum in hand and equipped with the battlesuit, Himeko prepares to battle the Herrscher of the Void. Though she is continuously overpowered by her, she continues to fight, though completely unable to touch her. She continues to take attacks, and her corrosion worsening to the point of almost completing the process of zombification, but she does not stop, as she wishes to save her student.
Himeko's face and body show signs of Honkai corruption
In one final attack, using up the rest of her strength, and with a lesson to Kiana to always continue to fight and change the world in the way she wishes to see it, Himeko brings down her greatsword on the Herrscher and... misses. Well, seemingly. Himeko never intended to hit the Herrscher at all. After all, she is using Kiana's body, and Himeko does not wish to hurt her. Instead, all Himeko did was for one purpose only: to get close enough. At this moment, while the Herrscher is stunned before her brain can process what's happening, Himeko injects the God-Slaying Spear, with the serum, into the Herrscher, forcing her out of Kiana's body. Having used up all of her power, Himeko peacefully passes away, as the world created by the Herrscher of the Void crumbles around her. Himeko's journey ends after saving her dear student.
Himeko stands, almost lifeless, over the Herrscher
Himeko's journey ends here, but her legacy does not. Kiana would adopt her ideals, fighting for the beauty she saw in the world. Despite it not being perfect, she would fight to turn it into the world she wants to see. Kiana would eventually take on powers similar to those Himeko displayed using the Vermillion Knight battlesuit, fully solidifying her legacy. Finally, they hold a funeral for her, only having the pieces of her sword that they were able to recover.
Himeko's sword fragments lay upon her coffin

Full Circle

13 years later, in 2029, Welt Yang finds himself traveling to a spaceship owned by the Sky People, along with his "friend", Void Archives. I won't go into too much detail about Void Archives, as his identity and details are not important here.
On this spaceship, they find the portrait of someone Welt recognizes: it's Himeko, but not the same Himeko he knows. Void Archives explains this is a Himeko from a world not the same as their own, and Welt decides that, since the Sky People were interested in her, she might be in danger, and he feels a sense of responsibility to help her.
Star Rail Himeko's portrait, visible on the left side slightly cut out
This leads to Welt and Void Archives, through yet unknown means, traveling to the world inhabited by the Himeko we see in Star Rail. From there, we know from lines in Star Rail that Himeko takes the both of them in, before Void Archives eventually leaves for some unknown reason, and that leads us to where we are today with Star Rail!

Conclusion

This ends the story of Himeko Murata! As always, some details were cut out to make sure everything fit in a decent length post. The last thing I want to point out is that, as you may have already seen, the Herta Space Station holds an easter egg to this story.
Shards of Himeko's sword, kept as a Curio
We can find the remains of Himeko's sword, as they were found in Honkai Impact. Though it's unclear how they got here or why, one can see that interacting with them while using Himeko brings some special dialogue, which you can see in the image above, as a small easter egg. This dialogue is a refence to a specific scene, the last scene in which we see HI3's Himeko, during the Everlasting Flames cutscene of the game.
\"Turn into a moon that always tells the warmth and brightness of the sun\"
Himeko appears one last time, within the flames brought about by Kiana's newfound powers. She smiles, before disappearing into the flames, solidifying her legacy within Kiana and her influence on not just her but the entirety of Honkai forever.
This ends the story of Himeko! Thank you very much for reading, and I hope you've enjoyed! Himeko is a very important character, perhaps not for her own characteristics or actions, but she is both the reason Kiana, the main character of Honkai Impact, is who she is today, and also the reason Welt ended up on the Astral Express, and why the Express can even run at all! I look forward to see how her story and character will develop now that we see her on this new path!
(As a side note, Himeko being keen on the Express and even able to fix it reminds me of a Himeko that continued to follow her father's path in being excited and fascinated by space, which is a very poetic thing, what do you think?)
As always, feel free to leave any suggestions, corrections or comments you wish, and I'll respond to everyone! Besides that, I'll see you next time!