She and her twin brother are working on a project on Eastern Han Dynasty costumes.

In 2126, Tsinghua University is a mosaic of technological wonders and cultural heritage, intertwined to form a place at the pinnacle of academic prestige in Beijing.

The most promising new students are the girl-boy twins, older sister Huo Xiao Yu and younger brother Huo Xiao Chen. While Xiao Chen had an aptitude for the subject that earned him steady praise, Xiao Yu's radiant beauty often overshadowed her academic performance. The proud recipient of the "Beijing Elegant Student Beauty" contest, Xiao Yu was an enigma—a blend of allure and ambition.

As freshmen in the history department of Tsinghua University, their academic pursuits revolve around the ancient costumes of the late Han Dynasty.

One sweltering afternoon, while sifting through the remnants of her grandmother's cluttered attic, Xiao Yu and Xiao Chen stumble upon an intriguing contraption wrapped in aged velvet fabric. Hidden beneath decades of dust and memories lies a time-traveling machine that their grandmother—a forgotten inventor—had carefully crafted. Her dreams of rewriting history through fashion remain unfulfilled, but she held invent the key to their curiosity.

As they unveiled the machine, they found strange symbols etched across its surface—symbols that pulsate with an ancient wisdom. The twin’s fascination grows when they read the handwritten notes nestled close by:

- ​​This guide is filled with scientific jargon that connects time and fashion. Users are advised to read carefully . The machine has a dual purpose: not only can it transport users back in time, but it can also analyze the threads and stitches of ancient clothing, revealing secrets about the lives and cultures of their ancestors. The machine is a two-seater, and can only take a maximum of two time travelers.

Xiao Yu stared at the machine with wide eyes and said:

- Little brother, do you see this? This must be the machine to travel to the past that our grandmother used to build when she was alive!

The machine has enough space for two seats for the two of us. We can use it to go back to the late Eastern Han Dynasty and see the costumes of that era up close. This tool will help our report get the highest score among the freshmen at the end of the semester.

Huo Xiao Chen leaned closer cautiously:

- It looks complicated... and a little scary. Are you sure it's safe to use? Grandma also left a booklet with warnings to be aware of when using this machine. Have you seen it?

Huo Xiao Yu picked up the thick booklet and touched on at the lines:

• Traveling into the past has two caveats:

• First, people who originally belong to the present world traveling to the past cannot wear clothes from the past world. Contrary, people who originally belong to the past world cannot wear clothes from the present world. The reason is that when you do that, you will see the phenomenon of clothes being transformed into their original material.
• Second, if the time traveler is stuck in the past for more than 3 years, he or she will be understood by the machine as a person from the past and he or she will not be able to wear clothes from the present era.

Xiao Yu said eagerly:

- Don't worry little brother, I've read it. The first warning said something like... "can't wear clothes from the past world" which is a bit confusing but I don't think it's too dangerous. Mainly the second warning might cause trouble, but I'll set a timer! Three years, right? We won't stay that long! We only have a few weeks to collect data, go back and complete our project.

Xiao Chen calmed himself down and replied:

- Okay, sister, I will listen. But if we get caught up in a historic incident, I will hold you responsible!

Xiao Wu happily said:

- Xiao Chen, this is why you are my cautious younger brother and I am my adventurous older sister! You want the Tsinghua University final report award, right? If we can analyze the fabrics and clothing styles of the Eastern Han Dynasty with this machine, it will be worth it! Stop worrying about anything and get on this machine with me.

Hou Xiao Chen sat on the chair next to her sister while Huo Xiao Yu ran her slender hands over the controls. The girl started by entering the "destination" box as Luoyang, then she continued to enter the "time to travel" box as the 3rd year of Zhongping during the reign of Emperor Ling of Han. The young girl's fingers moved over the shiny red switch. After 5 seconds, a small buzzing sound came from the machine while the lights flashed and the atmosphere became sparkling with possibilities.

With a shiver, the young girl-boy twins spun around, the machine emitted a blue light that illuminated the new space on the walls.

After determining that the space they had just landed in was the Great Han Empire in the 3rd year of Zongping, the twins held hands and stepped out of the machine.

The time machine now shrunk into a backpack that could be worn on the back. Xiao Yu continued to take command, she entrusted her younger brother with holding the machine and decided that they would both walk the streets of the capital Luoyang to research.

The bustling streets of Luoyang, 186 AD, were filled with merchants selling goods, children playing, and the aroma of street food wafting through the air. Xiao Yu exchanged glances with her younger brother, her words filled with excitement without a trace of worry:

- Little brother, can you believe it? We are really the world's first two time travelers! Look at all those people! Their sleeves are so wide and fluttering. They are truly people from nearly 2000 years ago.

Xiao Chen still cautiously reminded his sister:

- Remember, we have to focus on research to avoid getting into trouble and being stuck in this world for more than three years!

Xiao Yu smiled and promised confidently:

- Don't worry, there won't be any such incident. You know I can hardly live for three years without shower gel and skin care routine! Look at those girls in silk robes, they are so beautiful and graceful, I wonder what material their clothes are made of?

Xiao Chen replied:

- Grandma's machine analyzed that they are made of silk, this kind of clothes are often used by noble ladies

Xiao Yu's eyes sparkled with excitement as she said,

- If only we could blend in with them...get to know them. Xiao Chen, I want to wear the same clothes.

Xiao Chen nudged her sister's hand and reminded her,

- Let me repeat the warning about time travel that our grandmother wrote down: You can't wear clothes from the world in the past timeline, it will be troublesome.

Xiao Yu sighs:

- I already know. Let's go to a crowded street to test the machine's analytical function.