腹違いの兄弟？(Step Brother?)

Wait...WHAT!?!

Prologue
 
Shuffling can be heard within the All Might printed sheets as the greenette stirs awake with a small yawn following. He finally sits up with bed hair, rubbing the sleep out of his eyes while surveying the All Might merchandise filled room top to bottom, scratching his head as he rolls out of bed towards the bathroom. Brushes his teeth while trying, yet failing, to brush out the knots in his messy green curls silently wishing he had straight hair like his mama Inko. Finally giving up on his little adventure of the untamable forest called curly hair, he gets in the shower and presses his head against the cold tile wall to try to jog his memory about yesterdays’ discussion with his mom at dinner time. He’s interrupted by light knocking on the bathroom door.
 
“ Yes? ”, Turns the knob off to the water as he turns his head towards the wooden door with a small hint of curiosity.
 
“ Are you almost done? Company is coming over in 30 minutes. ”, Inko softly spoke.
 
“Yeah mom, I’m about to get out now actually”, He stepped out of the shower, promptly wrapping a loose towel around his waist, “ Who’s coming over anyways? “
 
“ Did you forget our conversation last night dear? ” He could hear a soft chuckle coming from the other side of the door alongside muttering something about forgetfulness? He couldn't quite tell to be honest as he dried himself off before slipping on a big light blue shirt that slid down one side, exposing his bare freckled shoulder, along with some mid-thigh black shorts with two thin white lines on each side.
 
“ Izuku, dear, some important guests will be coming over for dinner. I would like you to get to know their kids while they're here as well, I’m sure you’ll get along just heavenly with them, they are honestly sweethearts and are such gentlemen. “ She gushed before little footsteps could be heard lessening as she walked away, down the hall to the kitchen like every morning to start on breakfast.
 
Izuku tilted his head in confusion with a slight pout as his pointer finger lightly tapped his chin, wondering who these guests could be if they were this important to mom. Leaving the bathroom and returning to his room, the little greenette plopped into bed after grabbing his notebook off the shelf, off to another one of his many theories and daily analysis conquests, his computer already on Vtube to checkout the latest hero fights.
 
20 minutes later…
 
“ I wonder why All Might isn’t out on duty as often as before maybe...muttermuttermuttermutte-”
 
*Knock Knock*
 
“ Hm? Here already? Oh wait I forgot they would be coming soon.. Maybe I need more sleep?”
He sits up and closes his computer before settling his notebook back on the shelf and heads for the door. Walking down the hallway he can already hear chatter from downstairs along with laughter and.. Someone groaning? Who brought Mr. Grouchy Pants here huh? He checks a picture frame that shows him and his mom when he was 4 years old, holding up his first tooth in his little hand while wearing a big bright smile and that little gap his tooth used to be. He chuckled remembering that day, one of his more happier moments in his childhood as he continued to walk towards the stairs before stepping down each step, careful of the little creaks of the wooden planks. As he descends down the steps, his mom calls toward him, a sweet smile on her face as she speaks of pure joy and excitement.
 
“ Izuku, meet your new siblings and mother, Katsuki, Shindo and Mitsuki Bakugou!!”
 
“ Oh hi-” Wait a damn minute..,” Wait wait wait… WHAT!?”
 
“ Your new step siblings Shindo and Katsuki Bakugou should get to know eachother better while me and Mitsuki go set the table, have fun kids!”
 
Inko and Mitsuki walk past the teens towards the kitchen as Izuku just stands there, his eyes as big as saucers as he gapes like a fish out of water at this new piece of news just thrown at his face. Katsuki groans, glaring the greenette down with a deep scowl while Shindo just smirks with his hands tucked in his pockets. Silence fills the room as they all just stand there.