Bailu Youyun/Story

Her research focus is on the Sea of Data.^[9] As a result, she is away on trips often, even outside of the bubble universe, for around 12 months of the 18 of the Martian year.^[11]

Appearance

Youyun is a young-looking girl with long, light pink hair that is tied into two twintails. She has purple eyes with yellow pupils. She wears a short, warm-purple jacket over a light purple skirt.

Story

Part 2 Chapter X

Main article: Part 2 Chapter X

In Part 2 Chapter X, while Dreamseeker is in Difeng, Youyun is mentioned in relation to Sailin, having been said by Senadina to have helped improve her Spirit-Travel Box. This mention causes the three abebes of Dreamseeker to instantly stand at attention and start worrying about potential schoolwork. In response, Senadina explains that Youyun is also a student, leaving little time for her to assign work to others.^[8] She's secondly mentioned when Dreamseeker lies to Leylah, telling her of "energy gradients" that Youyun used to joke with her about when not wanting to teach. Her joke was meant to express her want to effortlessly transfer her knowledge into Dreamseeker's mind.^[2]

Personality

It is stated that Youyun's remarkable discoveries into Source Matter have earned her fame.^[12] She prefers to write introductions for topics with allure to people, sometimes neglecting other perspectives.^[13] When she writes, she is clear and descriptive, explaining specific aspects of the topic and responding to arguments against it.^[14]

Trivia

Before her debut, Youyun has been mentioned in various side quests and collectibles such as Calculability Representation of the World Continuum Hypothesis - Based on the Exploration Practices of the Sea of Data.^[15]
Youyun has a magazine issue generally titled "Youyun's Classroom", which teaches about Honkai Energy and the Great Eruption of Mars,^[16] though the author of the issues is rarely her.^[17]
Youyun appears to like writing in the second person.^[14]
She shares her Chinese voice actress with Hyacine from Honkai: Star Rail, Kachina from Genshin Impact, and Aria from Zenless Zone Zero.

Other Languages

Language	Official NameOfficial Name		Literal TranslationLiteral Translation
English	Bailu Youyun		—
Chinese (Simplified)	白鹿游云	Báilù Yóuyún	White Dew Drifting Cloud
Chinese (Traditional)	白鹿游雲	Báilù Yóuyún	White Dew Drifting Cloud
Japanese	白鹿遊雲
Korean	백록 유운	Baeglog Yuun
French	Bailu Youyun		—
Thai	Bailu Youyun		—
Vietnamese	Bailu Youyun		—
German	Bailu Youyun		—
Indonesian	Bailu Youyun		—

Navigation

See Minor Characters page for extra entries.

Notes

↑ Sector One's history occurs before Sector Two's, and the latter is set a hundred years ago.

References

↑ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 Part 2 Chapter I, Searching For a Trace
Helia: But just now, she mentioned Professor Youyun—is that your teacher, DreamseekerDreamseekerName can be customized by the player.?

DreamseekerDreamseekerName can be customized by the player.: Ah, that's right. She's our mentor, and also the director of the Data Research Institute.
↑ ^2.0 ^2.1 Part 2 Chapter X, The End of Chaos and Frolic
DreamseekerDreamseekerName can be customized by the player.: Uh... think of it this way. Your power flowed along the energy gradient of the Sea of Data into me. That's how I summoned the "fish servant" and ended the crisis. So really, I should be thanking you, right?

Leylah: My power drained away because of that?

DreamseekerDreamseekerName can be customized by the player.: (Of course — not really. That was just a joke Professor Youyun used to tease me with. I've heard it so many times I can spin it into any theory now...)

DreamseekerDreamseekerName can be customized by the player.: (She always wished there was an energy gradient between us, so all the knowledge in her head could flow straight into mine. Then she wouldn't have to teach, and I wouldn't have to study. Two birds with one stone.)
↑ 【视频】《崩坏3》8.6版本「谜宴丽影」宣传PV, Miyoushe
↑ @houkai3rd, X (Twitter), 03:20, Dec 26, 2025 (UTC -9) (Wayback Machine archive missing)

【出演】
遊雲（CV.#梅澤めぐ）
リタ・ロスヴァイセ（CV.#悠木碧）
#崩壊3rd
↑ Part 2 Chapter XI, Before Meeting in the Future
Gentle female voice: It's as if you've done something wrong — no, more like you "let someone down in the past, failed to live up to someone's trust". That seems closer to the truth. But you're a "child of the Sea of Data". You're not supposed to have a past, are you?

Professor Youyun's voice: I don't know. I just feel I still don't have the courage or ability to face you naturally. Like you said, I've only been out of the stasis pod for a year.
↑ ^6.0 ^6.1 Part 2 Chapter XI, Miracles Come for You
Youyun: *sobs*... I don't want to hear either of you talk! You two are so composed about everything, and even want to tattle on me to my parents. My mom and dad haven't been home for three years!
↑ Part 2 Chapter XII, We Still Have a Future
A bright, unreserved smile bloomed across Youyun's face. Perhaps because she had just mentioned her friend's name again, her tone softened slightly.

Youyun: Honestly, I've been so overwhelmed by the recent workload that I can barely catch my breath. But when I saw Leylah last time, I didn't sense even a hint of panic from her.
↑ ^8.0 ^8.1 ^8.2 Part 2 Chapter X, Three Possibilities of Wishing
Senadina: Maybe the outcome where all these possibilities coexist have something to do with Youyun's helping Sailin improve the Spirit-Travel Box. At this point, it has become a form of art.

"Dreamseeker" & Aseek & Dreamy: Youyun?!

Senadina: Why did you three suddenly stand at attention?

"Dreamseeker": We just suddenly felt like we should do so!

Dreamy: I feel a little guilty...

Aseek: Like wandering around outside when I haven't finished my homework.

Senadina: She's stressing over her own assignments, so why would she have time to assign them to others? If you really have any unfinished assignments, I can help you with them later.
↑ ^9.0 ^9.1 Part 2 Chapter XI, Performer in the Sunlight
DreamseekerDreamseekerName can be customized by the player.: When we visited the memorial hall, Senadina mentioned her name. I later inquired about her whereabouts: she's now working at the Sea of Data Research Institute.

DreamseekerDreamseekerName can be customized by the player.: Perhaps she's already noticed some anomalies related to the Sea of Data. After all, this was her research focus in Oxia, and she happened to have studied it more deeply than anyone else.
↑ ^10.0 ^10.1 ^10.2 Flowing Stars
An article written by Youyun, the 11th Director of the Data Research Institute.
↑ Part 2 Chapter I, Searching For a Trace
DreamseekerDreamseekerName can be customized by the player.: Since she's often on business trips, it's usually Chenxue who manages the day-to-day affairs of the institute.

[...]

DreamseekerDreamseekerName can be customized by the player.: Ah... sure, no problem. But when she goes on a trip, it can be quite a while—she might not be at the institute, or even in the bubble universe, for 12 out of 18 months a year.
↑ Message from Chenxue
"Don't rush to refute in your mind. Indeed, textbooks tell us that the Sea of Data holds endless treasures of all things, and through Source Matter, we can uncover any buried secret and obtain any resource we desire. But... Source Matter itself is so elusive. Perhaps we can gain only twenty percent from its infinite possibilities relying on our professional skills, while the rest depends entirely on luck."

"In the past, there were people like us who came here but left in frustration without gaining anything from these observations. And there are also people like Professor Youyun, who discovered extraordinary things within a week, thus earning her fame."
↑ Introduction to the Source Matter
A popular science article written by Youyun, the 11th Director of the Data Research Institute, introducing the concept of the Source Matter. You can imagine the expression on her face when she received this assignment—confusion, reluctance, and eventually compromise coupled with a heavy sigh.

[...]

When someone asked me to write an introduction to Source Matter for the newly completed Antares Building Civic Hall, I was actually against it. It's not that I have any biases against the requester— it's just that this topic lacks sufficient allure for any adult in Oxia.

[...]

The Civic Hall sets it up alongside the "Great Eruption" and "Oxia's History" as concepts of similar significance, and this perspective on addressing societal issues is indeed commendable. So, I will now directly excerpt several paragraphs from textbooks to help everyone recall the basic knowledge about Source Matter.
↑ ^14.0 ^14.1 Thought Experiment on Endless History
An article written by Youyun, the 11th Director of the Data Research Institute. It seems that Youyun really likes using the second person in writing.

[...]

Some may counter: the universe has a clear beginning and size, it's not truly infinite.

In the realm of physics, this is indeed the case. But within the realm of imagination, there exist more intriguing scenarios. Now, imagine yourself living in an online game.
↑ Calculability Representation of the World Continuum Hypothesis - Based on the Exploration Practices of the Sea of Data
A joint research paper co-authored by Chenxue and Youyun.
↑ Youyun's Classroom - Issue 101
A popular science magazine widely acclaimed by the public. This issue provides an in-depth analysis of Honkai Energy and the Great Eruption.
↑ Youyun's Classroom - Issue 103
Oxia residents often have this question: why is the magazine titled Youyun's Classroom when the author is always Chenxue?

[8] Sector One's history occurs before Sector Two's, and the latter is set a hundred years ago.

[INTRO-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 Part 2 Chapter I, Searching For a Trace
Helia: But just now, she mentioned Professor Youyun—is that your teacher, DreamseekerDreamseekerName can be customized by the player.?

DreamseekerDreamseekerName can be customized by the player.: Ah, that's right. She's our mentor, and also the director of the Data Research Institute.

[JOKE-2] 2.0 ^2.1 Part 2 Chapter X, The End of Chaos and Frolic
DreamseekerDreamseekerName can be customized by the player.: Uh... think of it this way. Your power flowed along the energy gradient of the Sea of Data into me. That's how I summoned the "fish servant" and ended the crisis. So really, I should be thanking you, right?

Leylah: My power drained away because of that?

DreamseekerDreamseekerName can be customized by the player.: (Of course — not really. That was just a joke Professor Youyun used to tease me with. I've heard it so many times I can spin it into any theory now...)

DreamseekerDreamseekerName can be customized by the player.: (She always wished there was an energy gradient between us, so all the knowledge in her head could flow straight into mine. Then she wouldn't have to teach, and I wouldn't have to study. Two birds with one stone.)

[3] 【视频】《崩坏3》8.6版本「谜宴丽影」宣传PV, Miyoushe

[4] @houkai3rd, X (Twitter), 03:20, Dec 26, 2025 (UTC -9) (Wayback Machine archive missing)

【出演】
遊雲（CV.#梅澤めぐ）
リタ・ロスヴァイセ（CV.#悠木碧）
#崩壊3rd

[5] Part 2 Chapter XI, Before Meeting in the Future
Gentle female voice: It's as if you've done something wrong — no, more like you "let someone down in the past, failed to live up to someone's trust". That seems closer to the truth. But you're a "child of the Sea of Data". You're not supposed to have a past, are you?

Professor Youyun's voice: I don't know. I just feel I still don't have the courage or ability to face you naturally. Like you said, I've only been out of the stasis pod for a year.

[PARENTS-6] 6.0 ^6.1 Part 2 Chapter XI, Miracles Come for You
Youyun: *sobs*... I don't want to hear either of you talk! You two are so composed about everything, and even want to tattle on me to my parents. My mom and dad haven't been home for three years!

[7] Part 2 Chapter XII, We Still Have a Future
A bright, unreserved smile bloomed across Youyun's face. Perhaps because she had just mentioned her friend's name again, her tone softened slightly.

Youyun: Honestly, I've been so overwhelmed by the recent workload that I can barely catch my breath. But when I saw Leylah last time, I didn't sense even a hint of panic from her.

[CH10-9] 8.0 ^8.1 ^8.2 Part 2 Chapter X, Three Possibilities of Wishing
Senadina: Maybe the outcome where all these possibilities coexist have something to do with Youyun's helping Sailin improve the Spirit-Travel Box. At this point, it has become a form of art.

"Dreamseeker" & Aseek & Dreamy: Youyun?!

Senadina: Why did you three suddenly stand at attention?

"Dreamseeker": We just suddenly felt like we should do so!

Dreamy: I feel a little guilty...

Aseek: Like wandering around outside when I haven't finished my homework.

Senadina: She's stressing over her own assignments, so why would she have time to assign them to others? If you really have any unfinished assignments, I can help you with them later.

[CH11-10] 9.0 ^9.1 Part 2 Chapter XI, Performer in the Sunlight
DreamseekerDreamseekerName can be customized by the player.: When we visited the memorial hall, Senadina mentioned her name. I later inquired about her whereabouts: she's now working at the Sea of Data Research Institute.

DreamseekerDreamseekerName can be customized by the player.: Perhaps she's already noticed some anomalies related to the Sea of Data. After all, this was her research focus in Oxia, and she happened to have studied it more deeply than anyone else.

[DIRECTOR-11] 10.0 ^10.1 ^10.2 Flowing Stars
An article written by Youyun, the 11th Director of the Data Research Institute.

[12] Part 2 Chapter I, Searching For a Trace
DreamseekerDreamseekerName can be customized by the player.: Since she's often on business trips, it's usually Chenxue who manages the day-to-day affairs of the institute.

[...]

DreamseekerDreamseekerName can be customized by the player.: Ah... sure, no problem. But when she goes on a trip, it can be quite a while—she might not be at the institute, or even in the bubble universe, for 12 out of 18 months a year.

[13] Message from Chenxue
"Don't rush to refute in your mind. Indeed, textbooks tell us that the Sea of Data holds endless treasures of all things, and through Source Matter, we can uncover any buried secret and obtain any resource we desire. But... Source Matter itself is so elusive. Perhaps we can gain only twenty percent from its infinite possibilities relying on our professional skills, while the rest depends entirely on luck."

"In the past, there were people like us who came here but left in frustration without gaining anything from these observations. And there are also people like Professor Youyun, who discovered extraordinary things within a week, thus earning her fame."

[14] Introduction to the Source Matter
A popular science article written by Youyun, the 11th Director of the Data Research Institute, introducing the concept of the Source Matter. You can imagine the expression on her face when she received this assignment—confusion, reluctance, and eventually compromise coupled with a heavy sigh.

[...]

When someone asked me to write an introduction to Source Matter for the newly completed Antares Building Civic Hall, I was actually against it. It's not that I have any biases against the requester— it's just that this topic lacks sufficient allure for any adult in Oxia.

[...]

The Civic Hall sets it up alongside the "Great Eruption" and "Oxia's History" as concepts of similar significance, and this perspective on addressing societal issues is indeed commendable. So, I will now directly excerpt several paragraphs from textbooks to help everyone recall the basic knowledge about Source Matter.

[TEoEH-15] 14.0 ^14.1 Thought Experiment on Endless History
An article written by Youyun, the 11th Director of the Data Research Institute. It seems that Youyun really likes using the second person in writing.

[...]

Some may counter: the universe has a clear beginning and size, it's not truly infinite.

In the realm of physics, this is indeed the case. But within the realm of imagination, there exist more intriguing scenarios. Now, imagine yourself living in an online game.

[16] Calculability Representation of the World Continuum Hypothesis - Based on the Exploration Practices of the Sea of Data
A joint research paper co-authored by Chenxue and Youyun.

[17] Youyun's Classroom - Issue 101
A popular science magazine widely acclaimed by the public. This issue provides an in-depth analysis of Honkai Energy and the Great Eruption.

[18] Youyun's Classroom - Issue 103
Oxia residents often have this question: why is the magazine titled Youyun's Classroom when the author is always Chenxue?

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[note 1]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]