Rain dripped down from the dark sky as it was raining cats and dogs, Koro-sensei started homeroom, the class noticed that his head was bigger than the usual.

"Koro-sensei, your head is approximately 33% larger. Please explain." Ritsu stated.

Koro-sensei's weak point

14) Prone to dampness

"Ah, it's soaked up all this moisture thanks to the high humidity." he answered.

After damping the water in his head, his face turned back like the usual one.

"Karasuma-sensei told me another transfer student is coming." Koro-sensei grinned.

"Yeah, well, probably another assassin."

"It'll be nice for you to have someone else on your side." he said.

"Hey Angel, have you heard anything about the fellow transfer assassin?"

"Nah, not interested." Angel replied, not showing a little bit interest of the subject.

"Well, how about you Ritsu?"

"Yes, a little. Originally, he and I were to be introduced together." Ritsu said to her classmate's question as she continued.

"I would handle long range attacks, and he will handle close range attacks. Together, we'd drive Koro-sensei into a corner, but those orders were canceled for 2 reasons." she said.

"Huh, were they?"

"Firstly, his adjustment took longer than expected and secondly, I lack the capacity to provide him support...As an assassin, I am inferior to him, I'm nowhere near his level."

"Ah—I remember..." Angel spoke as the class turned their attention to her,

"Slant eyes told me that a boy will transfer today, and there was something strange about this boy..." she stated.

"What do you mean?"

"Dunno, I didn't want to spent my whole day listening to his crap..."

Silence filled the room as the door slid opened, everyone turned they're attention to the door and to see a man in white.

"What's with that outfit?"

"Is that the new kid?"

A dove appeared from his hand as everyone flinched in surprise.

"Whoa, a dove appeared! Amazing, it's like magic~" A cheerful voice broke the silence as the man turned her attention to the speaker.

"Why thank you, pardon me but—are you that Yuuki Angel?" the man asked.

"Eh? Yeah, the one and only." she answered.

The class was startled at his actions as he turned his attention back to the class.

"Sorry, didn't mean to frighten you. I'm not the new kid—I'm his guardian, you can call me...Shiro." the man named Shiro said.

Some guy all in white comes in doing tricks? That will spook anyone!

"Well, not just Angel and Koro-sensei either—" Nagisa stopped his statement when he saw Koro-sensei turned into mucus and was stuck on the edge of the roof.

"Koro-sensei, you scaredy cat!"

"He's spooked enough to use his liquefy trick!"

Koro-sensei's weak point

15) Falls for rumors

"Well, Ritsu-san was telling all those scary stories! N-Nice to meet you though, Shiro-san...and where is our new student?" He went back on the ground as he was back to normal, Shiro get a pack of sweet in his sleeves.

"It's a pleasure to meet you, Koro-sensei. He's rather a unique child, in personality and otherwise." He stepped forward as he began to spoke once more.

"I'll introduce him myself..."

His eyes darted all the kids as he stopped at Angel, who's eyes were stained red.

"What is it?" Koro-sensei asked.

"Oh, just...you've got good kids here. Even an assassin is well maintained—I'm sure he'll fit in." He turned his attention at the door as the class did the same.

"Hey, Itona! Come on in."

The wall from behind broke into pieces as a boy with short, spiked light blue tinted white hair and shiny yellow eyes which appeared as the new student came in and sat beside the red-eyed girl.

"I won. I proved that I'm stronger than that classroom wall." he spoke.

"Use the damn door!"

"That's all that matters...that's all." he stated calmly, proving his strength.

The new student had a huge impact at the class, as Koro-sensei's reaction is a half-ass one.

"Horibe Itona. Please call him Itona." Shiro said.

Silence filled the class as all they could do is to stare at the newly arrived student.

"Say, Itona-kun. Something's been bugging me..." Karma said, as he find something strange about this new kid.

"You came in from outside, right? Empty handed? It's raining buckets out there, and yet there's not a drop of rain on you." he said.

Itona's shiny yellow eyes traveled along the room, as he stood up and walk towards the red head.

"You might be the strongest one in this class, but don't fret." He placed his head on his red hair and caressed it gently.

"You're weaker than me, so I won't kill you."

He took his hand away from his hair as he stood up straight once more.

"I don't get it...how the heck did ya blast the wall with no stuff in your hands?" Angel spoke as a shadow formed in the half of her face, her crimson eyes stared at his sunny gold eyes.

"Don't tell me you have that strange thing like Koro-sensei?"

He walked towards her as he touched her chin to force her to look at his eyes, "I heard that you were the first to inflict harm to Koro-sensei, is that true?"

"Yeah, I did. Have a problem about it?" she answered.

"Your strong, but weak in the same time." His hands left her chin as his eyes left hers.

"Huh?! What do you mean your strong yet weak?! Are you messing with me?" she retorted.

"Indeed your strong, but you know..." His finger touched her forehead as he flicked it.

"You have a weakness as well, that's why your strong yet weak."

I don't get what he means... she thought, confused.

"I only kill those who're stronger than me...and that is you, Koro-sensei." He said as he walked in front while he points his index finger at Koro-sensei who was chewing the sweets that Shiro gave.

"Who's strong and who's weak? That's how you pick your fights, Itona-kun? If it's a trial of strength, you and I aren't even in the same dimension." Koro-sensei stated.

"Sure, we are. After all, we're brothers by blood." He said as he gets the same sweets that Koro-sensei was eating from his pocket.

B-B-B-Brothers?!

Itona bit the plastic of the sweet, as his eyes looked at Koro-sensei.

"The loser dies, Nii-san. Siblings have no need for cheap tricks...I will kill you and prove my strength, after school—here in this classroom." He said as he closed the door as he and Shiro left the classroom.

"Now hang on, sir! What's with this brother stuff?"

"Humans and octopuses are nothing alike!"

"I haven't had any idea! I am an only child, when I ask my folks for a little brother things got really awkward." Koro-sensei was flustered.

"Wait, you have parents?!"

✦ ✧ ✦

Lunch Time

The class stared at how Koro-sensei and Itona can eat lots of sweets as they began to compare  the two who has a terrible sweet tooth, how they like big boobs.

"If they really are brothers...why wouldn't Koro-sensei know?"

Then Fuwa began to tell a tale, a manga about the two siblings.

✦ ✧ ✦

It was now the time for the face off, the tables and chairs were moved as the students hid behind them.

Itona took of his vest as beneath his clothes is a red colored desk ring, like this is a real match.

"You must be sick of plain old assassinations, Koro-sensei. Shall we lay down a rule here? How about...stepping foot out of the ring means death on the spot, what do you think?" Shiro announced his rule as the class heard it.

"Like the loser's gonna uphold that rule." Sugino huffed.

"No, breaking a rule that we were all about to witness would hurt our trust in him as a teacher. That kind of restriction works especially well with him." Karma explained to Sugino, then Angel sat one of the tables near Karma.

"Hey, Angel...stand behind the tables, you might get hurt." Nagisa warned.

"Don't worry, Nagisa! I will be careful." She said as she gave him a cutesy smile.

"Alright, I accept your rule. However, Itona-kun, hurting the spectators is also a loss." Koro-sensei stated.

"Start on my signal, Assassination—begin!" Shiro said as he waved his hand down, as the fight started.

In a split of moment, Koro-sensei's tentacle was destroyed.

They're eyes were all pinned to one spot—and it wasn't to their teacher's torn off arm, but to him...Tentacles appeared from Itona's hair, as it waggled freely.

"I knew it...you really do have that strange thing in your sleeves." Angel said as she knew it all along, that he had tentacles.

Oh, so that's how he stayed dry and empty-handed in that rain; he can bat away the drops with his tentacles. Karma thought as his question was answered.

"Where did you get those—those tentacles?!" Koro-sensei was now furious as his face turned into dangerously black.

"We're not obligated to tell you that, Koro-sensei. You two have different parents and past, but still you are brothers...My, what a scary face you're making, did you perhaps remember something unpleasant?" Shiro challenged him.

"It would appear like you and I will need to have a little talk." Koro-sensei said, angrily.

"But we can't. You'll be dead." the white clothed man stated.

Light appeared from his clothes as it triggers Koro-sensei's cells stiffen instantly. Koro-sensei shed his skin as he climbed at the top.

"You shed your skin? That's right—you had that trick up your sleeve, but Koro-sensei, we also know there's a weak spot there, too."

His tentacles flied to Koro-sensei who dodged it in a nick of time.

Koro-sensei's weak point

16) Right after molting

Shiro began to explain that his speed drops.

Koro-sensei's weak point

17) Right after regeneration

All the students could do is to stare at Koro-sensei who was in pinch.

"If this continues...he'll lose." Angel said as all she could do was to stare at her teacher who was hurt. She took a deep breathe before yelling.

"Koro-sensei! You can do it! Don't you dare to lose!" She yelled which cause the students looked at her, she was scared that Koro-sensei might really die in the hands of the new student.

"By my calculations, you should be evenly matched physically about now...it's plain to see who's in the lead now." Shiro said.

Angel continued to cheer for her teacher as the fight continued.

Koro-sensei's weak point

18) Hardens upon exposure to a special beam

A beam flash to Koro-sensei as Itona took this chance to blow a hit at his brother, numerous tentacles were destroyed instantly in one attack. Koro-sensei sat down, tiredly.

"Now you'll have to grow back your legs, too. That'll drop your stamina further, making you easier to kill." Shiro stated.

"Nii-san, I'm stronger than you." Itona said.

"Koro-sensei will die...if they kill him, they'll save the world!" Angel said as her eyes were concentrated at the ring.

"Kill him, Itona."

Itona was about to wave his next onslaught when Angel ran up and stood in front of Koro-sensei, shielding him.

"I won't let you kill Koro-sensei!"

"Angel-chan? What are you doing?" Koro-sensei was astonished.

There stood a brave student who protected her teacher from the enemy.

"I don't give a damn who you are, but I won't let you kill Koro-sensei! That's because...I'll be the one who'll kill him. We don't need you people in our assassination, we Class 3-E will surely succeed in this mission—I'll prove it to you!" Anger was written on Itona's face as he swung his tentacles,

I couldn't just stand and watch the person I care about get hurt! If I did—I'll surely regret it!

In a split of moment, Angel was protected by Koro-sensei.

"Thank you, Angel-chan. I won't die, I assure you, I want my students to be the one who'll kill me." Koro-sensei said as he turned to Angel.

"But you mustn't act hastily in this kind of occasion, you'll surely get hurt." he stated.

"B-But...If I don't act—It might be too late, and I'll surely regret it!" she reasoned out.

"Thanks. Go and seat behind those chairs, I'll win this fight, don't worry." Then he turned his attention to Shiro, with a smile that is plastered in his face.

"Shiro-san, there's one thing you forgot to take in account." Koro-sensei stated.

"There is not, my methods are perfect. Kill him." Shiro replied.

Itona's tentacles dug into Koro-sensei as his white tentacles were destroyed.

"I seem to have stepped in something you've dropped."

"Ah—the anti-sensei knife I was holding earlier is gone!" Angel said as the knife was gone, her eyes gaze at Koro-sensei, who's face was white.

When did he took it?!

Koro-sensei dropped Itona his shed skin, "If our tentacles are the same, then these anti-me knives will work to you, too."

Koro-sensei tossed Itona out of the classroom as the window broke into many pieces.

"You should be unharmed, and your feet is outside the ring." Itona took off the skin on him, as his tentacles were cut off.

"I win, so you die. You can't kill me anymore, if you want to live, stay and learn with everyone in this class, you lack experience. If you don't take my experience in this classroom, you'll never kill me."

"I won't? I...I'm weak?!"

Itona snapped as his eyes turned red, he unleash genocide from his tentacles as it turn black.

"I'm strong, these tentacles made me stronger than all the rest! All the rest!"

Itona attacked Koro-sensei but before he can, a bullet was shot through his chest as he fell on the ground.

"Sorry Koro-sensei, this boy isn't mentally prepared for school, he'll be taking a break." Shiro carried the wounded boy and was about to leave when Koro-sensei spoke.

"Wait! I'm his teacher, I shall look after him until he graduates and, Shiro-san...I have something to ask you."

"Yeah, no. We're leaving or would you stop us by force?"

The moment his tentacles touched his clothes, it was destroyed.

"You can't touch me. Don't worry, he'll be back before long, Koro-sensei." Shiro left the classroom, while carrying Itona on his shoulder.

"We'll be back, Koro-sensei. Before then, get ready to be killed."

The rain dropped from the sky once more, as the land turned wet.

I didn't expect that girl to be there...She still has that smell of danger, does she?

✦ ✧ ✦

Koro-sensei was embarrassed that the students witnessed his beast mode, he is usually the funny type.

Koro-sensei's weak point

19) Embarrassed when recovering after a serious scene

"Hey Koro-sensei, tell us!"

"How are you linked to those two?"

"You've always dodged about your true form."

But seeing that really gets us thinking.

"Yeah, we're your students, aren't we? Don't we have the right to know our teacher better?"

"The truth is, I'm a artificial life form!" Koro-sensei announced.

"Yeah, and?"

"We know that!"

"What we want to know is why were you so angry when you saw Itona-kun's tentacles!"

Koro-sensei was quiet, he didn't know what words to choose.

"Stop it, that octopus wouldn't probably talk about it." Angel said seriously, as Koro-sensei was still in silence.

"Each of us has one or two secrets of our own, if he prefers to keep it hidden, respect his decision." she added.

"Your a wise girl, Angel-chan. It's crude to ask after the number of one's appendages." Koro-sensei said, as Angel respected his decision.

"It's common knowledge, and...there are some things that are better off not knowing."

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EDITED ON APRIL 16, 2017
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