Synopsis: Yukimura, struggling to understand the female body, requests the help of Nora once more. However, Nora, being extremely bashful and also uneducated on the female body, they turn to the only person they can rely on... Sakigamiya Alice, the super smart, ultra charming, female leader of E Class. However, while Yukimura bargained for breast explanations, instead gets a shock when he learns what the menstrual cycle is.

Nora's POV:

It was a Sunday. A peaceful Sunday where I was away from all the troubles of school. After that close call in Ike-sensei's lab, I...

There's no point in lamenting over it. It's no wonder that Hideaki-oniisama had a girlfriend. That guy was always popular with the ladies. Who knew I'd run into one of his exes here.

That's beside the point. Today, I had the whole house to myself, since Kou was out today. I decided I'd take some time to relax and read a book to pass the time. I should've been studying, but... I didn't have the spirit to after what happened back there.

That was my plan for this mundane Sunday. Until...

Pin-pon. The doorbell rang. My heart began racing as anxiety clawed at my chest. Who could be there? Why did they know where I lived? That sort of stuff terrified me.

I braced myself and cautiously walked down the stairs. Each step felt stressful, filled with fear. I was shaking even though I held onto the railing. I stumbled towards the door and opened it slowly.

"H-hello...?"

Standing at the front door was just Yukimura-kun, who was in his casual clothes. It was just a black Abibas tracksuit. My heart calmed down and I opened the door fully. With the extended view, I saw he had a bag around his shoulders.

"Hey, Nora. Can you teach me about the girl's body?"

I looked blankly at Yukimura-kun. This is science related... right? In the first place... I don't know much about the female form either, so um...

"Why... couldn't you just have messaged me?"

"I was gonna head over to your place anyways to study anyways."

"But why my place..."

"Dude, look at how more comfy this place is. I'd learn way better in a nice environment like this than in my cramped room. It smells like sweat and socks in there, even after I sprayed cans of air fresheners." Yukimura-kun walked in, took off his shoes and plopped his bag on the table in the living room.

I think that's a you problem, Yukimura-kun...

"Anyways, I brought my science text book. I'm stuck on the biology section."

"It's good that you have an interest in science now, Yukimura-kun. Biology, hm? Which unit?"

"Homeostasis and hormones."

"Ah, this is why you were asking about the girls body earlier..."

"Yeah, so can you help me out?" Yukimura-kun sat down and unzipped his jacket. "Damn, it's warm in here."

I opened up the window to let the fresh spring air in. "Well, to be honest... I don't know anything about girls bodies either..."

"Ha? The super smart genius of our class doesn't know jack about a girl's body? Ha ha ha, what the hell?! I thought you were super smart at science!"

I felt hurt by his laughter. It made me like I was worth nothing. Or perhaps, that was the truth...

"Alright, if we're both dummies at the girls body, let's ask your roommate about it. Katsumi's a girl."

"But her grades are on-par with yours... she's only good at athletics."

"So someone like me, huh? We're in trouble."

"Well... there's one possible solution... for our problem."

"And that is?"

"Let's call in Sakigamiya-san."

Yukimura broke into an ear piercing cheer.

"ALLLLLLLRIIIIIIIIIIIIIGHTTTTTTTTTT! I CAN FINALLY FULFIL MY SENSEI FANTASIES WITH MY FAVOURITE GIRL! SAKIGAMIYA-SENSEI, TEACH ME MOOOOOOOOOOOREEEEEEEEEEEEEEEE!!"

I feel like I've summoned a demon...

Roughly half an hour later, Sakigamiya-san was at my house. She was in her casual clothes as well. As expected, she was stunningly stylish, with a low cut shirt and short skirt with thigh highs. I could practically see Yukimura-kun drooling.

"Sakigamiya-san! Thanks for helping me and Nora out!"

I still wondered why he used honourifics for Sakigamiya-san but not for anyone else. I don't have the bravery to ask...

"Not a problem! I'm happy to tutor both of you!" Sakigamiya-san said. She was really cheerful about this.

I'm not good at talking to girls, so I felt nervous and embarrassed. She took off her shoes, put on some slippers, and sat down at the table where Yukimura-kun was at.

"I'll bring us some tea." I said.

"Thanks Nora-chan." Sakigamiya-san said.

I left to the kitchen and let the two talk for a bit. When I returned with green tea, Yukimura-kun looked extremely puzzled.

"Men... strual... cycle?" He muttered.

"Yes, it's something a girl goes through every 28 days. How do you not know this? It's common knowledge." Sakigamiya-san said.

I nearly dropped my tray of tea when I heard that topic come up. Oh no... a girl like her... teaching us that... it would be so embarrassing!

No... keep it together, Takayuki! You can do this! It's just a natural part of human life! You have to learn this to pass your exams! If you don't, you'll...

You'll be... nothing more... than a...

Than a...

"Nora-chan, thanks for going through all the trouble of making us this. I really appreciate it."

Sakigamiya-san was standing in front of me, a cup of green tea in her hands. She took a sip and smiled refreshingly. I think she liked it...

Yukimura-kun snatched a cup from the tray and gave me a death glare. I-I'm not trying to steal your territory, I s-swear... he took a large gulp and licked his lips.

"Man, this green tea is good." He continued to drink it.

"Anyways. Back to the main point for why I'm here. If you want to learn about the female body, you first need to learn the menstrual cycle, a key process for women. It's essential to know, especially if you have a girlfriend. Being aware of her period and supporting her through this trouble is absolutely vital if you want to be a good boyfriend."

That was really good advice. Even though it wasn't directed at me, I still got a lot out from it. Deep down, I would like a girlfriend, but I know a guy like me... well, that'd be impossible.

For once, Yukimura-kun had a serious face on. Well, considering this was his crush talking to him and teaching him about relationships, I guess he'd take it seriously. Does that guy ever think about other things besides girls and football?

"Alright, that makes me even more pumped to learn about the menstrual cycle! Teach me, Sakigamiya-sensei!"

Yukimura-kun looked beaming when he got to use that nickname for her. Sakigamiya-san laughed at it.

"Oh, I'm a teacher now, am I? Very well then. Let our remedial class... begin!"

After we calmed and settled down, Sakigamiya-san began explaining to us the science behind the menstrual cycle.

"The menstrual cycle is a recurring process that takes around 28 days. During the process, the lining of the uterus is prepared for pregnancy. This means that if the implantation of a fertilised egg into the uterus lining does not happen, the lining is shed. This is known as menstruation, or otherwise known as a period."

"Wait... so the period isn't girl peeing blood?" Yukimura-kun said a nonsensical comment like that.

"No, no. The shedding of the uterus lining is the period. It's not nice."

"And this happens every 28 days... alright."

Yukimura-kun was making an honest attempt at remembering this. Considering it's Sakigamiya-san teaching him, he'll definitely remember.

"There are four hormones that are involved in the menstrual cycle. FSH, LH, oestrogen and progesterone. FSH stands for follicle stimulating hormone and causes maturation of an egg in the ovaries. LH stands for luteinising hormone and stimulates the release of the egg. Oestrogen repairs and thickens the uterus lining, and progesterone maintains the uterus lining. If you remember these four at least, you'll get an easy couple of marks on the exams. Menstrual cycle never fails to come up."

"FSH, LH, oestrogen and progesterone. They're such complicated names..."

"The names aren't that important. It's more important to know what function they have in the menstrual cycle."

"FSH grows the egg, LH releases the egg, oestrogen thickens the lining and progesterone maintains the lining. There, I remembered."

"Good work! I'll make sure to ask you what their functions are at the end, he he." Sakigamiya-san smiled cheekily. Yukimura-kun groaned.

"Now, this is how these four hormones work together to give women their period. Firstly, it starts in the pituitary gland, which is located up here, in your brain." Sakigamiya-san pointed to her head. "The pituitary gland produces FSH, which causes the development of an egg follicle in the ovary."

"What's an egg follicle?" I asked.

"Egg follicles are fluid filled balls of cells containing an ovum, or in simple speak, the egg. The FSH matures all of the follicles, but one grows faster than the other. That matured egg is the one that will get released."

"Ah... Okay." I nodded.

"Now, the egg follicle has the ability to produce oestrogen. This occurs while the egg develops inside the follicle. Yukimura-kun, what does oestrogen do?"

"It... uhh... repairs and grows the lining!" Yukimura-kun snapped his fingers.

"Good, good. You remembered!"

"Don't treat me like a little kid, I know what I'm talking about."

"If you know what you're talking about, then why don't you teach Nora-chan the remainder of the lesson?" Sakigamiya-san crossed her arms and looked smugly at him. Yukimura-kun flinched.

"N-no, you can teach him, Sakigamiya-sensei... I'm just here to go over this topic again. Yep."

Yukimura-kun would make for a convincing liar if he wasn't struck with nerves due to talking to Sakigamiya-san. I laughed a little bit.

"Anyways, before we were rudely interrupted by Yukimura-kun, we know that the oestrogen causes growth and repair of the lining of the uterus wall. However, there's also a second reason why oestrogen gets released. You see, oestrogen inhibits FSH. In simple speak, this means it stops the FSH being produced."

Yukimura-kun scratched his head. "Why does that happen?"

"If the FSH continued being produced, more eggs would mature. If that happened, more than one egg would be released by LH, and that'd be disastrous for the woman, wouldn't it?"

"Yeah... if you got pregnant with more than one egg in the womb, that'd mean you could give birth to like ten kids!"

"Exactly. When oestrogen rises to a high enough level, it causes a surge of LH to get released from the pituitary gland. This surge in LH will cause ovulation, which is when an egg is released from the follicle. This occurs midway through the cycle, on day 14. Now, the follicle turns int something called the corpus luteum. Corpus luteum produces oestrogen and progesterone, which both inhibit production of FSH and LH in the pituitary gland. This is an example of negative feedback. Nora-chan, do you know what negative feedback is?"

I panicked when Sakigamiya-san turned to me for an answer, but I had definitely heard of it before. Yukimura-kun gave me a condescending look, as if pressuring me to answer.

I could hear his voice taunt me, "Yeah Nora, what's negative feedback, huh? Don't breathe in the presence of Sakigamiya-sensei ever again, or else I'll kill you, you smarty pants." with a knuckle crack. It was a terrifying thought...

"Um... n-negative feedback... is um... a mechanism to... l-lower raised levels of something... and to raise reduced levels of something... I think..."

"That's correct! Good job." Sakigamiya-san reached over and patted my head. Yukimura-kun looked shocked, and gave me a death glare.

I could hear him silently threaten, "If Sakigamiya-sensei rewards you again, I'll kill you!" with a knuckle crack.

I looked down at my lap and closed my eyes. My cheeks felt all hot and bothered. I was frightened, embarrassed and happy...

"The progesterone's job is to maintain the thickness of the uterus lining. Simultaneously, oestrogen will continue to repair and grow the uterus lining. Did you two follow that so far?"

I nodded. Yukimura-kun squinted his eyes, stroked his chin, and nodded. He was trying his hardest to impress her...

"Alright. There's only one last step. If the egg has not been fertilised, the corpus luteum dies, and the progesterone level drops. As a result, this causes menstruation, which is?"

"The uterus lining breaking down. In other words, a period." Yukimura-kun said.

Sakigamiya nodded excitedly and gave a thumbs up. "Nice one, Yukimura-kun! That's exactly what happens!"

Yukimura-kun smirked and flicked his bangs, pretending to be an intellectual ikemen. I give the effort a 11/10, but the execution a 4/10... his face is just too scary to be considered attractive.

While Sakigamiya-san looked through her text book and notebook, Yukimura turned to me and stuck up his two middle fingers.

"Take that bitch." Yukimura mouthed to me. He then started to point them at me. I felt extremely uncomfortable and shuffled back slightly.

I really don't want to get hit by Yukimura-kun... it hurts a lot... I got a bruise last time and it took weeks to go away...

I fiddled with my thumbs and waited for Sakigamiya-san to finish reading over her notes.

"Alright, so in the case the woman does get pregnant, the placenta, an organ in the uterus, produces progesterone. This is important because maintaining the lining during pregnancy means menstruation does not happen. Alright, quiz time! Yukimura-kun, tell me two hormones involved in the menstruation cycle, which gland they come from, and their role."

"Uh... FSH is produced in the pituitary gland and causes maturation of the egg in the ovaries. It stimulates the ovaries to release oestrogen. LH is also produced in the pituitary and causes the ovulation of the mature egg."

"Ooh, I loved that answer! You used lots of keywords too, well done!" Sakigamiya-san smiled widely. Yukimura-kun rubbed the bottom of his nose in confidence. He gave me a sharp glare as if telling me to go ahead and fail to make him look better.

Why is he so scary... I really don't like it...

Maybe it's because he reminds me of Fuyukichi-san from middle school...

She was similar to him... in a twisted way. After all, both were excessively friendly to me, but when it came down to it, both would knock me down if the situation called for it.

While Yukimura-kun gave me bruises, Fuyukichi-san tore apart everything that was precious to me.

I remember standing in the middle of the library, tears overflowing my eyes, and water dripping from the ends of my hair. The book in front of me was soaked, and the pages melded and merged into a soggy mess all over my feet.

My hands were trembling with loose, transparent, ripped pages draping over my fingers. They laughed at me. Again and again. Until their faces went red and tears were in the corner of their eyes.

I wondered that day why I believed someone would save me.

"Nora-chan, are you okay? You looked... really depressed right now." Sakigamiya-san gently shook me out of my dark memory.

"...oestrogen and progesterone are both produced in the ovaries. Oestrogen inhibits FSH and repairs or thickens the uterus lining. It stimulates the pituitary gland to release LH. Progesterone inhibits LH and maintains the lining."

Sakigamiya-san nodded. "...that's correct, Nora-chan."

Her voice sounded more serious than before. I shifted uncomfortably, holding my arms close to my body.

I shivered. When did it become so cold...?

"Do you guys wanna take a break?" Yukimura-kun said.

"Yeah, a break is a good idea! Looks like Nora-chan's brain exploded for a moment there, ha ha ha." Sakigamiya-san laughed.

I appreciate Sakigamiya-san trying to lighten the air, but... it's just making it colder. I looked up and bit my bottom lip.

"I'm... sorry... I just... remembered something that... something from my..."

"Hey man, we all have those moments. Don't sweat it." Yukimura-kun nudged me with his elbow.

"Forget about it now. We're at a new school with all the freedom in the world. Whatever happened in our pasts are meaningless." Sakigamiya-san agreed.

Yukimura-kun looked down with irritation and disappointment. Sakigamiya-san looked away with disgust and spite.

I selfishly wanted to ask... what their pasts were like.

Part 2 exploring contraception and ways of treating infertility coming soon.