This is gonna be a different thing y'all, just so you know. This is going to go oldest to youngest in Sakamaki's, then the same for the Mukami's, then the same for the Tsukinami's. (In different chapters).
So, the layout will kind of look like the one shot books. Trust me, I'm not gonna stay doing this layout, this is only for this one request.
Request: Daddy reacts to new boyfriend (Sakamaki, Mukami, and Tsukinami.)

Shu

The girl was surprisingly calm. For a big step of her life, she maintained to be calm, knowing not to get much of a reaction. The warmth of a hand tangled up in hers reminded her of the deep love.

Y/N pulled the bigger hand towards to mansion, entering through one of the big doors. "Don't worry, he's really calm," she whispered to the boy, feeling the shaking that came from his nerves.

"I'll always be okay with you," he tried to cover up the little fear with a smile, being dragged along to the big moment. The comment made the little girl smile, trying not to show it as she came closer to the adult vampire.

"Stay here for a minute," she looked back at him, letting her hand slip away from his as she turned away. She made small footsteps to the couch the vampire was laying on, stopping right in front of it.

The little girl brought her little finger to poke the bigger vampire, one eye of the bigger vampire opening. "Daddy, I have someone you need to meet," the girl smiled down at him, turning around and waving the boy over. The boy slowly walked over, posture as neat as can be when he took his steps.

The sharp blue eye shifted over to the boy causing chills to run down his spine. "Sir, it's a pleasure to meet you."

Oh my dear god.

Y/N had a quick giggle, attempting to cover up the formal and short greeting. "Daddy, this is B/N, and he's also my boyfriend."

"No I'm not," the boy quickly added.

What?

"Of course, not without your permission, sir," he got down on one knee. Dear god, did Reiji raise you or something?  "Sir please bless me with presence of your lovely daughter for the rest of my life."

Jesus have mercy..

Shu stared at the boy for awhile, not a word coming out of his mouth. Finally his mouth opened, the little girl scared for the answer, "Whatever," he said turning to face the backside of the couch. A smile hastily spread across the young girl's face, looking to the young boy and hugging him.

"Was that a yes?" the boy whispered in confusion, hugging the girl back. Y/N giggled at the confusion the boy had held.

"Yes," she whispered back.

Reiji

Knock.

Knock.

Knock.

The young girl turned her head to look at the boy behind her. "Do you have the papers?" The boy nodded as an answer, showing her proof of the papers in his hands. She look down to the papers that had been shaking as much as his hands were. Her hand automatically went to his, latching onto his firmly, "It's okay," she smiled at the boy. The boy looked up to her, a tinted red appearing on his cheeks as he smiled back and nodded.

Creek~

The young girl quickly removed her hand from the boy's, facing forward to see her father standing before her. She saw Reiji take his sharp eyes off her and to the boy, his eyes narrowing. "Father, may we come in?" her hands folded together behind her back as she smiled up to the bigger vampire. His eyes came back to the girl, nodding.

"Yes, come on in," he moved out of the way and opened the door some more as the two kids entered the room. The two kids took a seat as Reiji made his way to make some tea. While the vampire was making tea the two kids looked at each other, one was shaking with fear still, the other calm as ever. Y/N mouthed to the boy "It's okay, I'm right here," she smiled. The boy nodded, the words going into his thoughts but not into his heart as he continued shaking. The girl frowned, looking over to her father.

Reiji soon finished the tea, setting it on the table in front of the three. "So, Y/N, please tell me why you wanted to meet," he finally spoke when he had taken his seat, lifting up his teacup and taking a sip of the liquid.

"Yes, father, this is B/N. B/N and I have been to know each other more and he wants to ask you a question," she switched the spotlight to the nervous young boy.

"Sir, please listen to me as I request this life changing wish. Sir, I have had fun getting to know more about your daughter and I have become addicted to her. Please, sir, let me take your daughter's hand and guide her to my heart as she did to me. Please, let me love your daughter till the end." B/N took out the papers he was told to bring, "I promise I will get a good job with these grades and lead her to her haven."

Reiji eyed down the A's covering all of the papers, not one bad grade coming into sight. He looked back up to the two kids, his eyes stopping at the girl, sliding the grades back to the boy. "Y/N, you have met a fine boy. I approve." Y/N showed a small smile, nodding.

"Thank you, father."

Ayato

How's he gonna react? Is he gonna say no? Is he gonna embarrass me? Is he gonna laugh? Why can't my dad just be normal? Fear clotted the little girl's mind, scenarios filling the clots. "Stay out here and wait for me, okay?" the girl smiled at the boy as she opened the big mansion doors, closing them behind her. "Daddy!" the little girl's yell echoed throughout the mansion, the red-headed male bound to hear.

"What?" Ayato suddenly appeared before the girl, looking annoyed as ever. More anxiety rushed through the girl, now knowing that it was for sure going to happen.

"Listen here oreo-sama, whenever I bring in this person, I want you to be completely nice, no 'go make me takoyaki' because it's not gonna happen!" the girl viciously whispered to the older vampire, glaring him down.

"Tch, no one bosses ore-sama around."

"Oh, do you really want to test that out? I know all your deepest darkest secrets," she threatened him, smiling afterwards and opening the big entrance doors. "Okay, you can come in now," she smiled to the boy, getting out of the way so he could enter.

B/N entered, being eyed down by the older red-head. "Okay, daddy, you ready?" she smiled at Ayato.

"Yes." Ayato answered.

"Yes." B/N answered.

Why can't you keep your stupid mouth shut...

"Haha, that's really funny, now B/N please explain what's going on," Y/N quickly changed the topic, sweat rolling down her cheek. The sharp narrowed green eyes were now stuck on the young boy, a deadly look on the vampire's face as he just stared.

"Oh, okay. Uhm, dad, I guess I'll call you that for this question. Dad, I li-"

"Don't call me that," Ayato interrupted in annoyance.

"Okay, uhm, mister, I li-"

"Don't call me that either."

"Okay....uhm, sir-"

"Ore-sama," Ayato demanded the kid called him by a specific name. Y/N silently sighed to herself, feeling bad for the young boy.

"Oh, okay, Ore-Sama, I like your daughter and I'm basically asking you if your daughter can be my girlfriend," B/N looked at the older vampire, seeing  if there was any clue of the answer on his expression. The room got silent, Ayato changing his view from the boy to Y/N, seeing her puppy eyes activated.

"Whatever, but you can never beat Ore-Sama," he looked over to the boy, very reluctantly accepting his answer.

Kanato

"Daddy," Y/N spoke, seeing the back of her father in the living room. "I have someone I want you to meet." She smiled as the small purple-haired vampire turned around, waiting for the someone. Y/N waved over a young boy hiding out in the entry way. The boy came out of hiding and attempted to walk over to the girl with a calm manor, failing as his whole body was shaking in fear.

"U-uhm, nice to meet you sir! I w-wanted to ask your premission for something very important," the young boy started out nervously, the girl interrupting.

"Why don't you introduce yourself first?" she smiled to the boy, looking to her father to check his expression. It wasn't pretty.

"O-oh, y-yeah, my name is B/N. I come from the same school as her, two classes together. Through the time learning with her, I got to know her better, a-and I really got to l-like her. Sir, it would make my day if you approve of me and her being together. I promise to take goof care of her, I won't let anyone take her away from me. Please consider it." the boy looked as if he was going to get down on his knees and beg, showing desperation. Y/N's eyes were glued to her father's expression, looking for some kind of sign.

The room filled with the tension of Kanato's narrowed eyes and B/N's pleading eyes. Kanato looked over to Y/N, Y/N pleading him with just her expression. Kanato looked at Y/N for a few minutes before looking back over to the boy. "I'll kill you if you break her heart," he giggled a little.

"I won't, I won't ever break her heart!"

Laito

"It's going to be okay! He's a really calm guy, trust me," Y/N reassured the little boy, making sure there was no fear.

"You've said that one hundred times now, I'm starting to question if you're talking to me or to yourself," the boy sighed when hearing the same sentence once again.

"You're the one who didn't speak in one single class all day today! I'm trying to cheer you up," she frowned upon hearing that she was getting annoying.

"Fine, you win, just don't frown, it's making me feel bad," he pinched her cheeks upwards, creating a false smile. She swatted his hands away, her expression annoyed. "Haha! So, you're sure he's here?"

"Mmhmm! He always greets me whenever I come home from school..for some reason. So, he should be here to greet me," she smiled at the boy, answering gleefully.

"Alright then, you take the lead, m'lady," he moved out of her way, bowing as his arm stood out and pointed his open hand to the big doors.

Y/N walked her way up to the doors, opening only one of them. Once the door was wide open a red-head with a fedora on came into view. "Daddy! Good timing, I wanted you to meet someone important~," the little girl moved out of the way so B/N could make his entrance. "Daddy, this is B/N. B/N is here to ask you something important."

Laito was looking at the boy as if he already knew what was coming, "Uhm, first of all sir, your daughter is the most beautiful creature I have ever seen. Second of all, me and your daughter have developed feelings for each other. I wanted to take her hand and take our liking to each other into a deep love, of course I will never do so without your permission. So, please grant this wish of mine and let this liking become more," the young boy finished the request, his expression showing no fear whatsoever.

"Of course you can, fufu~! Just be sure Y/N doesn't forget her sweet father~!" Laito easily accepted the request, taking the young boy by surprise.

"Y-yes sir!"

Subaru

"Daddy! There you are!" a soft breeze played with Y/N's hair as she saw the person she was looking for. "Daddy, I know I still might be young and all, but I have something really important that happened. I would love if you could listen, daddy," she smiled seeing the red crimson eyes look at her.

"What did Laito do to you?" he already sounded annoyed.

"Nothing, daddy! Nothing!" she waved over a boy with (H/C) hair, the boy calmly walking over to her. "Daddy, this is B/N. B/N and I have really gotten to know each other and we want to become....lovers..? B/N," the girl hunched the boy in front of her, allowing him to speak. Subaru's cheeks tinted red whenever he found out what the topic was going to be about. He realized it was a bad mistake being a single parent.

"Sir, I have already gotten my parent's permission, and it would be great if I could get the same answer from you. I promise you with all of my heart that I will protect your daughter in anyway I can, I won't let anyone try to steal her away from me. I will do anything to get your approval for this, if it means I can stay with your daughter forever, I'm willing to do anything. Please sir, let me take care of your daughter," the boy finished, only the wind being heard now.

"Tch, go ahead, it's not like I can stop any of these feelings anyway," he responded as normally as he could, trying to hide his blush by looking away with crossed arms.

Y'all that was hard...and yes i know none of them said no, i didnt know if you guys wanted them all to say yes or give their own answers...comment down what you want and yeah..