Present day~~~~~~~~~~~~

A very tired and angry looking Rin, Bakugo flung open the door of class 1-A and took his usual seat next to his best friend Yuki, Shigaraki without a word to anyone.

"Good morning sunshine." Yuki joked seeing the familiar scowl on his friend's face.

"I'm not in the mood Yuki. Dad pushed me past my limit again last night and he and mom were fighting again." Rin grumbled.

"Well have you talked to Shinso about it?"

"No cuz then they'd fight about it like they always do." Before Yuki could question Rin a familiar hyper girl ran up to them.

"Good morning guys!"

"Saji?" Rin asked,

"Yeah?"

"Shut up. It's too early for you."

"Jeez, okay than Mr.Grumpy pants. Parents fighting again?" She asked in a hushed tone so no one else would hear her.

"Yeah. Dad pushed me to my limit again. I burnt my hand, mom found out and yelled at dad, dad set off an explosion, mom used his quirk to get him to fall asleep then this morning he yelled at mom for using his quirk on him." Rin explained.

"What happened to the no quirks in the house rule?" Yuki asked

"Dad." Was the only answer he got from the purple-haired boy. Before the trio could continue there talk Aizawa walked in the room with the number two, three and four heroes. Rin quickly put his head down as he knew his classmates would be looking at him. It wasn't a secret that he was the child of the number two hero ground zero. Everyone in the class knew, and probably the whole world. But luckily for him, he did not have the classes full attention but rather shared it with Koru Todoroki, he son of the number one and three heroes. Koru's parents were none other than the number one hero himself Izuku Midoriya, aka Deku, and Shoto Todoroki who was the number three hero. As for the number four hero, he was none other than Eijiro Kirishima who's son was in class 2-A.

"Morning class, as you can see here I have with us the second, third and fourth heroes here with us. Now I'm all sure you're familiar with the fact that we have the parents of two of your fellow classmates and one parent of a student in 2A. So please, try not to ask too many personal questions. Now with that being said listen up and respect the heroes before you." Aizawa stated in a rather bored yet serious tone.

"Rin, come up here now!" Bakugo yelled to get his son's attention. Rin looked at his friends with a nervous look but quickly replaced it with the standard Bakugo smirk. Rin stood next to his dad in front of the entire class unsure of what he had planned for the boy. "Now as you all know I am Katsuki Bakugo, father of Rin Bakugo and the number two hero. Today Icyhot, Kirishima and I are here to answer some questions and train you brats for the day. Now any questions?" Yuki looked at Rin and smirked before raising his hand and asking,

"Yeah, can Rin go back to his seat now?" The entire class looked over at the redheaded boy in horror. Bakugo glared at the teen as he asked,

"Name and quirk." Yuki smiled and stood up,

"Yuki Shigaraki, Hellfire quirk." He stated proudly.

"Oh, so you're my son's little friend," Bakugo said before turning his attention back to the class. "Anyone have an actual question for me or my son?" He asked. Saji raised her hand and stood up,

"Um, hi I'm Saji Kaminari and I was just wondering what kind of quirk training will we be doing?" Bakugo gently shoved Rin's shoulder as a cue for him to answer the question.

"You'll fight amongst each other than go one on one at some point with my father or one of the other pros." Bakugo nodded approvingly.

"My son is correct. Today the three of us will pair you with one of your classmates, then you will each have the chance to fight with one of us." Bakugo said. Rin looked at the floor for a moment thinking of how excited all of his classmates must be getting to show off against a pro when for him, it was just another one of his dad's training sessions. Rin's classmates continued to ask his dad questions about the training program until one question from none other than Kuro Todoroki caught his attention.

"Is Rin's training at home just as extensive as ours will be today?" The whole class went quiet. No one had thought about how this would be only one day of thorough training for them, but could possibly be just another workout for there fellow classmate.

"Don't you worry, well Rin does spar with myself on the daily I can assure you he will be going one on one with a different pro hero." While that didn't answer his question entierly, Kuro decided to leave well enough alone. Once Bakugo was done answering questions Rin was allowed to sit back down, where he promptly laid his head down on the desk and while Todoroki talked for a few minutes attempted to take a quick nap. As Rin snoozed he was woken up by the sound of a blast.

"What the hell dad!" Rin yelled only to find a very angry Bakugo before him.

"Pay attention when Kirishima is talking." Was all he said to his son before going back to the front of the room.

"Thanks, Bakubro. Anyway, sup kids, my name is Eijiro Kirishima hero number four. I have a son in class 2-A and I work closely with all the other pro heroes, so feel free to ask me anything!" He said enthusiastically. Rin looked on in dismay at the red-headed hero before him. If there was on hero he did not like, it was Eijiro Kirishima. The number four hero and his dad were extremely close and shared a bond similar to that of he and Shinso's. This disturbed the teen as he was well aware of their past relationship and wondered if there could be more to the story that he was not aware of. Kirishima and Bakugo worked together on a majority of hero missions and so, Kirishima, arguably, got to spend more time with Bakugo then Rin did. This resolution lead to hatred from both Rin and Shinso. Shinso did not think the amount of time the two spent together was a good thing. Shinso gave up his dreams of being a hero to raise Rin, and how did he get repaid? By having his husband run around doing supposed hero work with his ex-boyfriend and baby daddy. Shinso tried to keep his feels towards Kirishima a secret from his son, but eventually, Rin developed his own feelings of hatred towards the number four hero. Yuki noticed the sour look on his friend's face and leaned over to whisper ina smug tone, 

"What's wrong, not a Red Riot fan?" 

"Shut it Yuki. That wannabe hero spends more time with my damn dad than I do." Rin quietly responded. Yuki nodded, he understood how hard it must be for his best friend. After all Yuki's parents are villains so it's not like he sees much of them. Once Kirishima was done talking and answering questions, Bakugo once again stepped forward. 

"Alright listen up, I'm going to be assigning you to a group with a pro hero, once you're in that group the pro you have been assigned to will pair you up to face off once on one. Once the pro you are with decides you've warmed up enough, you get to face off against them. Everyone clear?" The entire class nodded and awaited further instruction. Rin listened for his or his friend's names to the called. Yuki was in Bakugo's group, Saji in Todoroki's and Rin ended up with none other than Eijiro Kirishima. From that point on the class followed their respected groups into the training arena. From there they were paired off and told to start training immediately and only stop when the pro you're working with tells you. Rin was paired with Kuro Todoroki. Yuki and Saji were paired up with some extras Rin hadn't even heard of before, but regardless he was confident in his friend's abilities to kick ass. Rin and Kuro went to there respected section and started sparing at once. Kuro's quirk was ice and Rin knew exactly how to use that to his advantage. As the two spared Kuro started to ask questions. 

"So, I noticed you had a sour look on your face when Red Riot was talking, any particular reason?"

"Shut up you special snowflake, we're here to fight not to talk about our feelings!" 

"Fair enough, but I'm just curious as to why you hate him so much. Does it have to do with the fact that the two dated and had a kid?" Rin froze dead in his tracts, smoke started to pour out of his tightly clenched fists. 

"What are you talking about icicle?" 

"My dad Izuku told me that. Did you really not know? Iwa is your half-brother. But then again maybe they didn't want you to know, oh no did I just reveal a secret, oh daddy won't like that, what if it gets dad in trouble, what if I get in trouble-" An explosion broke his rambling. The boy's head grew foggy and so did his eyesight. Everything became muffled except for the sound of Rin's voice. 

"Who is Iwa Kirishima?" Before the boy could think the words came flowing out of his mouth. He was hit with Rin's quirk.  

"He is Kirishima and Bakugo's child, he was born after they graduated but the two couldn't agree on how to care for him so they split up," Kuro said in a trance-like state. 

"How do you know all of his for a fact?" 

"My dad Izuku Midoriya told me all of it, but my daddy Shoto Todoroki said I had to keep it a secret."

"Why cousin? Why did my uncles keep this secret from me?" Rin asked in a hurt tone. Kuro Todoroki was his cousin, his family. While it may not be by blood but by the simple friendship of there parents, Rin still grew up with his cousin. They went to school together, did homework together, they even applied to UA together. 

"Kirishima, Bakugo, and Shinso agreed to never tell you about your older brother out of fear that you two would only hate each other." Rin stopped using his quirk and released his cousin. Kuro was light-headed and fell to his knees before looking up at his cousin. "I'm sorry Rin."

"No, it's fine. I just wish I didn't need to use my quirk on you to know the truth."

"Hey, Rin! Nice job out there, why don't you spar with me now?" Kirishima said. The purple-haired boy looked back at his cousin, then to the hero before him. He nodded before walking away from his cousin. He needed answers and this fight was how he was going to get them.