"The formula for determining the midpoint of a segment in the plane, is..."

And with one sentence, half of the students in the 2-1 Geometry class fell asleep.

Nakano Azusa valiantly tried to listen, but her attention span was getting shorter by the second. Mutilated diagrams of line segments filled the board as the professor continued to put everybody to sleep. Every five minutes, someone yawned, loudly.

"I can't take this anymore!" The bored guitarist glanced at the clock, only to be severely disappointed. It turns out, a mere fifteen minutes has passed since the start of class. She glared at the clock and sighed.

"I wonder how Jun's doing..."

Despite being seated in front, Jun managed to fall asleep without getting caught. There was a small puddle of drool on her notebook, which oddly had a cat sticker on the cover.

"Wait... That's my notebook!" Jun had better start borrowing notes from someone else, because Azusa sure as hell won't be lending her anything for a while. She looked around to see if her other friend fared any better.

Unsurprisingly, Ui was still wide awake. Judging by the amount of scribbles on her notebook, she probably took good notes, and even seemed to be enjoying the class. Azusa checked to see if the teacher was looking, and quickly passed Ui a note.

"If only Yui could be more like you..."

A worried frown inched across Ui's face as she wrote her reply.

"Did nee-san forget something again?"

"No, that's not it."

Somehow, Ui's reaction made her smile. It was easy to see why she constantly worries about her sister. Living with her was like living with a child, albeit a very noisy child who loves to eat, refuses to get out of bed, and frequently forgets important things. Sometimes, she forgets that Yui is actually her sempai.

"Then what is it? She refused to practice again, didn't she?"

Azusa's thoughts jumped to what happened yesterday. A new member whom she knows nothing about just joined the group, and she happens to sit next to Yui. Now would be a good chance to find out more about her.

"You know that girl that sits beside Yui?"

"Tachibana-sempai?" The abrupt change in topic puzzled Ui.

"What do you think of her?" The raven haired guitarist impatiently bit her pencil. Ui's opinion of the newcomer might give her some valuable information.

"I've never had the chance to talk to her personally, but she seems to be a really nice person." Then again, to Ui, everybody is nice.

"Let me guess, she lets Yui copy her homework." Surprise, surprise.

"She's nice in other ways too, you know." A slight blush covered Ui's cheeks as she struggled to defend her sister.

"Like what?"

"I think you should ask nee-chan instead." The cryptic reply only served to aggravate Azusa's curiosity. She stood up quietly to walk over to Ui's seat.

Meanwhile, the professor has finally realized that half of his class had fallen asleep. The remaining few who were awake seemed to be half-dead. Their apathy irritated him. Just as he was about to walk out, an eager student suddenly made a stand in the sea of indifference. It brought tears to his eyes to see that there was someone who still cared. The professor's voice was choked with emotion as he called out the only student who volunteered to answer his question.

"Nakano-san, will you please tell me the formula for determining the measurement of this angle?"

"Er... Uh..." Azusa mentally berated herself for standing up. She glanced around to see if anyone would help her. Even Ui was stumped. Sighing in defeat, Azusa was about to sit down silently, just as a random memory surfaced in her head.

Geometry was always a challenge to Azusa. There were too many formulas to master, and most of them made little or no sense.

Above all, she hated senseless things.

She threw her notebook to the floor in frustration, but hastily picked it up. Her sudden outburst of anger embarrassed her, because she didn't wan't anyone to see her throwing fits over a simple equation. It was lucky that the music room was empty at the time.

Or so she thought.

The doors to the music room whooshed open, as Yui rushed in to hug her angry friend. Unfortunately, Gitah's weight turned the hug into a tackle, and both of them ended up on the floor.

"O-ow... Yui-sempai!"

"You look so cute when you're angry!" Yui grinned widely. Then her attention suddenly shifted towards the discarded notebook.

"What's that?"

"N-nothing. Just my notebook." The kouhai quickly put it back in her bag.

"Why did you throw it? Did you get a paper cut?" Azusa found her hands immediately covered in cat-shaped bandages.

"What? Of course not!" Honestly, Yui can be such an airhead at times. A caring airhead, but an airhead nonetheless.

"Oh. Then why'd you throw it?" Big, brown eyes stared with unrestrained curiosity at the notebook.

"The lesson... It's hard..." It took a great deal out of Azusa's pride to tell Yui that she didn't understand something.

"Fear not, little Azunyan! For I, Yui Hirasawa, shall help you defeat this notebook!" Insert flashing eyes and cheeky grin.

"You. Help. Me...?" "That sounds wrong."

Yui yanked the notebook away and stared at the pages. Azusa watched quietly, and decided to wait for Mio's arrival. After all, she somehow managed to make Ritsu pass calculus. Learning geometry from Mio should be a breeze. Now, if only she could get her notebook back.

"Ready for your lesson?" Yui put the notebook in front of Azusa.

"Lesson? What lesson?"

"The one I'm about to teach you!" Yui gave her kouhai an odd look.

"Huh?" The raven-haired girl stared back blankly.

"Geez. No wonder you can't understand geometry. You don't listen very well, do you?" If anybody else said that, it would have been an insult. But since it came from Yui, Azusa quietly swallowed her pride and nodded in defeat.

"So, how do we start?"

"Hmm. Well, basically, your lesson is all about angles, so let's focus on that."

"O-okay." Yui was actually making sense for once. The serious look on her face was making Azusa nervous.

"Think of them as cakes." Scratch that.

"Cakes?" Azusa waited to see if Yui was joking.

"Cakes." She wasn't.

"Right." "At least she tried to help..."

"Well, a 360° angle is like one big cake. Then a 270° angle is three-quarters of that cake, while a 180° angle is one half of the cake. Get it? Now what's the 90° angle?"

It took a moment for Azusa to admit that the metaphor actually made some sense. She decided to give her friend some credit.

"One-fourth?"

"Right!"

"So how do I find the measurements?"

"By eating the cake!"

"Eating the cake. Uh-huh." Credibility has its limits.

"See here. So it's one big cake, right? When you want to find the measurement, you just take a slice out of it!" Fortunately a cake was lying around. Professor Yui used it to simulate the process of angle measurement. She also ate it.

"Oh, I see! So I subtract it!"

Somehow, Yui's lack of sense actually made everything else easier to understand.

"Huh? What's subtract?" mumbled the ditzy guitarist while licking the icing off her cheeks.

"Just cut the cake and measure the gap."

"What?" The professor found the solution highly confusing. After a brief silence, Azusa realized that she had to translate Yui-speak to something more normal.

"The complement of the angle, if subtracted from the supplement, should give us the answer, provided that they are both vertical."

"Nicely done, Nakano! It sems that you listened well to today's lecture! You deserve extra credit for tomorrow's quiz." The students raised an uproar when they found out they had a quiz tomorrow. In the background, the clock's irritating tick reminded everyone that there was still half an hour to go.

"Note to self: Give Yui some cake. Strawberry cake."

And with that thought, Azusa fell asleep.

A/N: No Mitsu to be seen here. Haha. :P