White Blood Cell sipped his tea as he sat next to Red Blood Cell.

It always felt nice whenever they got to spend time together. Whenever there was an opportunity to take a break and have a chat, or visit an organ, or even just sit in comfortable silence, he enjoyed spending time with his favorite erythrocyte.

A few days before, Red Blood Cell was on high alert. The blood pressure rose, and the heart was beating quite fast. Stress hormones flooded the place. After a while it relaxed a bit, but the heart rate and blood pressure didn't really go down to normal until the stress hormones stopped being released, which finally happened after about four hours of fast-paced circulation. He wondered what all that was about.

Stress

The body will release stress hormones, such as adrenaline, when confronted with adverse circumstances. In theory, this allows the body to react in emergencies, but in non-emergencies, it can be quite a hindrance. The heart rate rises, and blood vessels constrict. One can be stressed from a number of stimuli, from excessive homework, to loud noises, to riding on an airplane.

White Blood Cell breathed in deeply. It was very peaceful at the moment, just sitting on the bench with Red Blood Cell, watching various erythrocytes walk past them down the path. Red Blood Cell was dozing at this point. She kept closing her eyes, leaning towards him, before waking up with a start and doing it all over again. It was quite adorable, honestly.

The peace was broken when White Blood Cell heard a loud bing! as his sensor detected an antigen in the area.

Red Blood Cell started, but she didn't fully wake up.

White Blood Cell closed his eyes and rubbed the bridge of his nose. "I'm sorry, I have to go. I'll see yo-"

Thump.

He opened his eyes has he felt a soft weight on his arm. Red Blood Cell had completely fallen asleep, and she fell asleep against him.

I don't have time for how cute this is.

Feeling very, very guilty about possibly disturbing her, White Blood Cell stood up as slowly as he could. He gently laid Red Blood Cell down on the bench, making sure she was secure, before running off down the blood vessel to find the antigen.

…

"Nǐmen dōu zhuā bù zhù wǒmen! Hahahahaha!"

"Get them!"

U-4989 heaved as he chased after the bacteria. The fuzzy pink bastards were quick!

"Antigen sighted!" yelled a familiar voice.

"1146!" cried 4989 as his friend came out of a connecting vein and leapt into action, knives unsheathed.

U-1146 almost managed to hit a bacterium, but it dodged at the last second.

"Damn it," he grumbled, "those things are quick!"

"Well, don't just stand there!" 4989 shouted as he ran past his friend.

They chased the bacteria together up the blood vessel with the other immune cells, but soon, the bacteria split up into more and more groups. Even when reinforcements were called, the bacteria seemed to evade every strike. They went down the many different blood vessel pathways winding through the intestines, fleeing from the exhausted immune cells.

U-1146 bent over, gasping for breath. Bracing himself on his knees, he tried to steady himself.

"Dammit… hah, hah, those dumb pink balls of sick are fast… hah, hah…" U-4989 was panting even harder than U-1146, sides heaving in and out.

1146 brought his radio to his mouth and started calling for backup. "Be on high alert, there's a lot of them, and they're really hard to catch."

4989 sat on the ground. "Man, I could really go for a nap."

1146 straightened up immediately. "Oh! Damn! I almost forgot!"

"Forgot what?"

"I left Red Blood Cell sleeping on a bench! I should go make sure she's not in danger!"

He turned back to go get her when several erythrocytes came his way, hoisting a gigantic red… ball… thing.

"What the heck is that?" asked 4989.

…

Red Blood Cell's eyes fluttered awake as she realized she was on the bench alone.

"Wha- what?! Oh!"

She quickly sat up, her head still groggy. How long was she out? Where was White Blood Cell-san?

She rose to her feet, slightly off-balance. She rubbed her face and blinked the sleep out of her eyes.

"Ohhhhh…" she groaned.

Looking around, she saw no sign of White Blood Cell anywhere.

I guess he had to go fight germs, she thought sadly.

Red Blood Cell was very grateful that he was so dutiful in his never-ending job to protect the body. Still, she often wished she could spend a little more time with him without interruption. He was her boyfriend, after all.

Oh, well.

At least he let me sleep, she thought, smirking. He's so thoughtful like that.

She looked around and saw all the erythrocytes going pest her bench were all moving in the same direction. Her eyes flicked to the wall, where an arrow pointed the direction of blood flow. She was getting much, much better at navigating. She had two whole pages in her notebook filled with tally marks of successful circulations, and she was almost a quarter way finished the third.

She stood up, stretched, and began to walk down the path. She may have been tired, but she still had work to do.

Off to the lungs, I guess.

…

The giant red ball baffled everyone.

"What is it?" 4989 asked no one in particular.

The cells all stood around the ball that the erythrocytes put down in the middle of the path. Most of them continued on, but one, an erythrocyte with auburn hair in a long plait, stayed behind. Other erythrocytes entering in the blood vessel swerved around the weird object.

"No clue," said the auburn-haired erythrocyte. "I can't even read it."

On the side of the capsule were some writing, next to a small red rectangle with a large yellow star in the upper left corner and four smaller stars in a vertical arch around that. The writing was in two lines: the top line said "抗生素," while the bottom line said "中国产."

The characters looked similar to Kanji, but some of them were unfamiliar to the cells.

U-1146 was studying it carefully. "The top row looks like it says… 'kosei…' something… maybe antibiotic? Strange… I've never seen it written like that."

"What does the second line mean?" asked the auburn-haired erythrocyte, crossing her arms and squinting at the strange writing.

U-1146 squinted closer at it.

"Hmm… I'm not sure of the pronunciation… Maybe 'chu… Chuugoku?' 'Middle Kingdom?' I'm not sure what that means. And I've never seen this Kanji before in my life," he said, pointing at the character "产."

U-4989 stood near the auburn-haired erythrocyte, also squinting at the strange writing. "It looks like someone started writing a Kanji, but then got lazy and stopped… maybe it rubbed off on its way down?"

The erythrocyte looked at him. "Then why are all the other characters perfectly fine?"

4989 shrugged. He opened his mouth to respond, but then he caught sight of a familiar (and sleepy-looking) rebellious red curl emerging from the entrance, surrounded by other erythrocytes.

"AE-3803! Hi!"

U-1146 turned to face the entrance. Sure enough, there she was, looking quite grumpy having been woken up from her nap.

He felt his mitochondria twist. She was so cute when she looked grumpy and pouty.

Fortunately, he thought she was also very cute when she looked happy too, since she smiled and waved tiredly when she saw her friends.

"Hi everyone! White Blood Cell-san, 4989…" she trailed off mid-greeting and stopped walking as she began to doze standing up.

"Hey now, don't forget AC!" 4989 said.

Red Blood Cell started as she woke up again. "Ah! Yes! Sorry, I'm just… so… tired…"

"Did she… fall asleep again?" asked 4989.

The sleepy erythrocyte began to tip over. U-1146 ran up to her side and caught her, holding her gently so that she wouldn't wake up.

AC-4293 chuckled sympathetically and placed her fingers over her mouth as she looked at her fellow erythrocyte. "I completely understand what she's going through. My feet are still killing me from a few days ago. I hope I get a delivery to the nasal cavities soon, I could really go for a footbath."

A mechanical whir filled the air.

AE-3808 woke up with a start. "Wah! What? It wasn't me!"

Everyone looked towards the red ball. A line formed and grew in the middle as the sphere split in half and flipped open. Inside, strange flying things flew out.

They were black, square-shaped devices, with propellers attached to each corner. In the very center, a ball-shaped bulge hung down, four nozzles sticking out of it. On what appeared to be the front end were printed two images: the small red rectangle with the five stars, and a red star with the Kanji for the numbers eight and one arranged vertically in yellow inside of it. On the sides, there was another strange logo. It looked like a strange, crescent-like object, with a small circle at the bottom, crossed over what appeared to be a hammer. The meaning of all the symbols were lost on the cells, but symbolism was the least of their worries.

"WHAT ARE THOSE?!" screamed AE-3803

"Tóngzhìmen hǎo. Wǒmen xiànzài qù zhǎo jūn, zhǎodào jiù shā jūn," the flying things announced in monotone unity. They dispersed, spraying some kind of chemical in a fine mist from the rotating nozzles on their underbellies.

"They look like some kind of antibiotic, but I've never heard that language before!" exclaimed U-1146.

Antibiotics

Antibiotics are substances that target and kill bacteria. They work on bacteria by targeting certain enzymes that the bacteria produce, disrupting the bacterial cell wall, or preventing bacteria from reproducing; as such, they are ineffective against viral, fungal, or parasitic infections, since they are not bacteria.

The mechanical drones repeated their greeting as they spread out and went down various blood vessels, coating everything underneath them with mist. AC and AE both began coughing.

1146 inhaled deeply. "Yep. Definitely smells like antibiotic."

"They need a new smell," croaked AE-3803 as she tried to stop coughing.

Bing! Bing!

Both U-1146 and U-1148's receptors activated. The two neutrophils glanced at each other.

"Antigens," the said in unison.

"Stay- cough, cough- stay safe!" called out AE-3803

"Be careful! Cough!" cried AC.

The neutrophil pair bounded down the blood vessels in pursuit of their enemy.

A/N:

The drones coming from the ball is a reference to the steroid in the anime, which came out of a ball as well. In reality, there is no way an actual pill would fit into most blood vessels.

Of the three symbols on the drones, I think the star with the Kanji may be the most obscure. That is actually the symbol of the People's Liberation Army, China's military. The Hanzi and Kanji are the same for the numbers eight (八) and one (一). These numbers are the date that the army was founded, August 1, 1927. Since the antibiotics are like robotic military drones, I thought it would be appropriate to put the military's logo on them.

Chinese Translations:

"Nǐmen dōu zhuā bù zhù wǒmen!" - You can't catch us!

抗生素 - antibiotic(s)

中国产 - Made in China. "中国" is the same characters in both Hanzi (Chinese Characters) and Kanji (Japanese Characters), literally meaning "Middle Kingdom," and actually meaning "China." "产" means "to make" or "to produce."

Tóngzhìmen hǎo - Hello, comrades

Wǒmen xiànzài qù zhǎo jūn, zhǎodào jiù shā jūn. - We will now search for the bacteria, and kill them when we find them.