"My biology lesson is different from normal. I'll also teach you a general knowledge about biology, but I'll also teach you something else."
Haru stood up in front of everyone and attracted their attention easily.
"What kind of thing will you teach us, Sensei?" Yaoyorozu asked.
"What I want to teach you is how to understand your ability better," Haru said.
"Understand our ability better?"
"Yeah, for the answer to my question before, you can think of it for a long time, but before that, you need to become stronger since being a hero is a dangerous job. If you're stronger then you'll have a chance to keep your life, catch villains easily, or save someone in dire situations."
Haru moved to the board and wrote something on it.
"Quirk Factor?"
"Yes, Quirk factor." Haru looked at everyone and asked, "Do any of you know what it is?" He looked at Yaoyorozu who raised her hand. "Can you explain it to us, Yaoyorozu?"
Yaoyorozu nodded and stood up.
"The term "Quirk Factor" refers to the collective physical and genetic traits that compose a person's Quirk. This includes the primary Quirk power as well as all the biological mechanisms that allow said primary power to function properly."
"......"
"Yes, that's a good answer, but it is too complicated since I can see that some of you aren't smart enough to understand what it is." Haru smiled looking at Kaminari and Ashido.
"........"
Kaminari and Ashido blushed, but they felt that Yaoyorozu's explanation was too complicated.
"In simple terms, you can understand that a Quirk Factor is something within our body which gives us an ability." Haru looked at everyone again and said, "Some of you have a tail, some of you can make an explosion, some of you can release acid, etc; the reason all of that is Quirk Factor."
Midoriya wrote everything that Haru had written. He understood that he could use All Might's power because All Might had given his Quirk Factor to himself which made him understand the reason why he only needed to eat All Might's hair in the past.
"Bakugou."
"What?"
Bakugou stared at Haru at this moment.
"Can you release the explosion from your feet?"
"........"
Bakugou shook his head and said, "No, I can't do that."
"Only your hands?"
"Only my hands."
Haru looked at Yaoyorozu and asked, "How about you Yaoyorozu? The thing which you've created always comes out from your chest, right?"
"Yes." Yaoyorozu nodded.
"How about your hands? Can you release the things you've created from your hands?"
"No, I can't do that." Yaoyorozu shook her head.
"Mineta, what about you? Can you just create that sticky round thing from the hair in your head? Can you do it from other places?"
"Huh? Another place?" Mineta was confused.
"How about the other hairs in your body? Or is your body so smooth that you don't have hair beside your hair in your head?"
Everyone chuckled when they heard Haru's words.
Mineta complained and said, "Sensei, I have hair in that area!" He couldn't admit that he was smooth on that area since it would damage his pride as a man.
"Oh-ho? Then can you produce the sticky thing from the hair from that area?" Haru asked.
"......"
Mineta twitched his lips and shook his head. "I can't do it, Sensei!" Even if he could, he wouldn't use it since it was disgusting. He couldn't think of the possibility of throwing his sticky thing from his pubic hair.
"Midoriya."
"Y, Yes?!"
Midoriya was startled when his name was being called and wasn't sure why.
"I've seen that you've gotten hurt from the last exam."
"Y, yeah..." Midoriya became depressed.
"You can't control your ability very well?"
Midoriya was embarrassed and depressed, but nodded regardless.
"I'm not sure the reason, but I've three hypotheses why you can't control your Quirk."
"Huh?"
"First, your Quirk is so strong that it damages your body and because of that you've never used your Quirk, but from Bakugou's expression yesterday, I can see that both of you have known each other for a long time and if you've a Quirk at that time then his reaction won't be this aggressive."
Bakugou stared at Midoriya deeply at this moment.
---
All Might wanted to come out since he was afraid of Midoriya's identity being disclosed by Haru, but he was stopped by Nezu and Aizawa.
"Why?!"
"That's my question, what are you doing?" Aizawa stared at All Might.
"....."
All Might wanted to say something, but he closed his mouth.
"Believe in him." Nezu stared at All Might.
All Might sighed and nodded.
---
"...."
Midoriya panicked and wasn't sure what to say.
"So the first reason hypothesis is impossible since I can tell that you don't have a Quirk when you're young, right?"
"......"
"You don't need to answer me and let me say my second hypothesis." Haru looked at Midoriya and knew that this guy had a secret, but he didn't feel that curious about it. "The second hypothesis is that you've awakened your Quirk during your 3rd year of middle school. Even though it is rare, it isn't impossible."
"Y, Yeah! I, I've awakened my Quirk in my 3rd year of middle school." Midoriya was smart and he hurriedly nodded.
Haru nodded and said, "Then it is quite understandable that you can't control your Quirk. Then let's continue with my third hypothesis."
"Third hypothesis?"
They thought that it was over, but they didn't expect that Haru would continue.
"Do you have a teacher?" Haru asked.
"Huh?"
"I want to ask, do you have a teacher who is teaching you about your Quirk?" Haru asked again.
"......."
Midoriya nodded at that moment.
Haru nodded and said, "Then your teacher sucks at teaching."
"......"
---
All Might, who was outside, twitched his lips.
Aizawa and Nezu shook their heads since they knew that All Might sucked at teaching.
---
"First, let me remind you that Quirk isn't something special. Just think of it as part of our bodies."
"......"
"From your expression, I can see that you've been thinking that Quirk is something special, right?"
Midoriya nodded.
"From my observation yesterday, when you used all of your power within your fingertip to throw that ball, right?"
"Yes."
Midoriya nodded and didn't feel that nervous anymore since it seemed that Haru didn't know anything about the relationship between him and All Might.
"That's the wrong way to use your Quirk."
"Wrong?"
Haru nodded and said, "You, who has only received your ability for a while, use your work very crudely. As I've said before, Quirk is part of our bodies so it always exists on our body. You shouldn't use it as if it's a device which you turn on-off. You should erase the on-off button on your head and have always used it on your entire body spreading it out evenly, not only to your finger or arm, but all of your body."
Midoriya was stunned at that moment.
"If your body can't handle 100% of your power, then use 20%, if you can't do that then lower it again and again until your body has gotten used to your ability, do you understand?"
"Yes, Sensei!"
Midoriya felt that the door had been opened and all of the things which had made him confused were cleared at this moment.
---
"...."
All Might blinked his eyes at this moment.
"It seems that he's a better teacher than you." Nezu smiled.
All Might nodded and seemed happy when his successor had become stronger.
---
Haru nodded and said, "Now, you must be curious why I've asked that question, right?"
They nodded.
"The answer why you can only use your ability from some parts of your body is because of your Quirk Factor. The Quirk Factor in your body only exists within your body, then the real question is, can you release your power from other parts of your body? Can your ability become stronger? The answer is obvious... Of course!"
Haru moved his finger which turned into a zipper before it transformed into a small drill. What he wanted to teach them was creative thinking. If they could think creatively then it was possible for them to become stronger faster.
"So you're ready to receive my teaching?"
"Yes, Sensei!"
Everyone thought that this might be their favorite lesson.