Inko eventually just invited Mitsuki to have dinner with them on New Year's Eve and then they left the Bakugo household. For some reason Nana couldn't quite fathom, Inko seemed to think the trip had been a complete disaster or something. Nana and Mitsuki had gotten along fine! She couldn't see what the problem was! (The only downside was that she and Mitsuki hadn't managed to have that fight…)
New Year's Eve arrived and Nana returned from her morning jog to find…
"There you are Nana! Well are you going to let me in or leave me out in the cold!" said Gran Torino.
"Sorahiko?! What are you doing here?!"
"I'm waiting for you to let me in. Obviously!"
"Wha-wait a minute. Was this your plan?!"
"Yes."
"WHY?"
"Because I felt it would be best to get a survey of the situation myself. And no I didn't tell your boy. If I had this apartment block would be rubble by now. Also, I wanted to meet my honorary grandson!"
"Oh no, he is not your honorary grandson! Because that would make you honorary grandfather and that would make us-" They both shuddered.
"Grand-nephew then! And I am his Grunkle!"
"That's better. Well then- "
The door opened and All for One stuck his head out. "What is going on out her- "
Gran Torino kicked him in the face.
All for One staggered backward and gave a pained grunt. He looked at Gran with a (literally) murderous expression.
Inko came out of the kitchen and gave all of them one of her rare (yet terrifying) death glares. "What is going on here?"
"Hi Nana!" Gran said to Inko with his faux senile tone. He looked at Nana with his phony glazed eyes. "Who are you?"
"Oh! Who are you sir? Do you need any help?" Inko said.
"I just defeated my arch nemesis Salaryman!" Gran said pointing at All for One in his business suit (he'd finally gotten one back from the cleaners and put it on like he'd been naked without it.)
Inko seemed to buy the "senile old man act". "Oh, I'm very sure. Now why don't you sit down for a minute while me and my family talk. And don't worry about 'Salaryman'. He won't be doing anything." She turned to Nana and All for One and gestured to the corner of the room.
The family gathered. Inko turned to Nana, "Mom, who is that?"
Nana grimaced. "That's Sorahiko Torino. Hero name: Gran Torino. Me and him are um, friends. We did hero work together. He lives a few cities over"
"And you just let that poor old man travel all the way here alone! Shame on you! What if he'd gotten lost?!"
"Hey I didn't know he was coming here. He does what he wants!"
"How can you let a poor senile old man just do whatever he wants?!"
"Trust me he's more capable than he looks," Nana said shooting a glare at Gran.
Gran (filthy faker that he is) got up and doddered toward the kitchen. "I'm going to help you make Taiyaki Nana!" He said to Inko.
"Oh what a sweet old man! You don't have to worry, I'll handle everything. You just sit down and watch TV. And my name's Inko." Inko said, trying to gently push him toward the couch.
"Ok! I'll do that Mrs. Inko!" he let himself get pushed.
"Coward", Hisashi thought.
"Traitor," Nana thought.
Dinner finally came (no thanks to Gran who seemed to enjoy being allowed to mooch) and the Bakugos arrived. They all gathered at the table ate, chatted, and overall got along quite well. Izuku and Katsuki both had their high chairs next to each other and half ate, half played with their food. Overall everything was going fine.
"It's so nice of you to spend time with your family while home from classes young man. As a former teacher I could help you with your thesis-" Gran said in his faux senile voice
"For the third time old man, I graduated college years ago!" All for One snarled.
"Now now Hisashi, calm down, Mr. Torino is probably just forgetful in is advanced age," Inko said. "Sorry about him, he gets insecure about how young he looks (personally I'm kinda jealous of it myself). So, Mr. Torino, what was training All Might like?" Inko asked.
"Hard. That man could be a real idiot sometimes. And his combat technique needed brushing up. So, I came up with a highly-specialized instruction technique."
"And what was that?" Mitsuki asked.
"I kicked his ass until he got better!"
All for One looked positively delighted to hear that. "Please do tell. I'm sure you have so many stories to tell us."
Mitsuki said "How do we know that's actually true? I mean this is All Might we're talking about and-"
Gran Torino got out his phone and quickly dialed a number and motioned everyone to be quiet. It rang a few times before being picked up.
"Y-yes Gran Torino? W-what is it you'd like to talk about today?" The unmistakable voice of All Might said.
"What am I not allowed to wish my student a happy New Year?!" Gran Torino said.
"N-NO! I-I mean YES! I mean of course you are! Happy New Year yourself!"
"Good. Happy New Year to you too. Brings back memories… Speaking of which, would you like to spar again for old times' sake someti-"
"OH LOOK AT THAT! A KITTEN STUCK IN A TREE! GOTTAGOBYE!" The phone hung up. Gran looked over at Mitsuki with a very smug expression. "You were saying?"
"HELL YEAH! I WANNA HEAR ABOUT ALL MIGHT BEING BEATEN UP BY A SHRIMP LIKE YOU!" Mitsuki yelled.
"Volume Mitsuki. And language around Izuku," Inko said.
"Sorry Inko."
"Well ok, since you asked Mrs. Bakugo…", Gran proceeded to tell them several embarrassing stories about training Toshi. Nana would indignantly leap to her so-SUCCESSOR's defense…if she weren't too busy laughing at his expense. Though she did feel bad that All for One was also enjoying her successor's past misery.
"You beat him up until he vomited?! Oh, what a sight that must have been! The Symbol of Peace with the power to level buildings spending his training getting beaten to a pulp by a man with only a propulsion Quirk. I bet he still gets nightmares!" All for One laughed.
"It's not that funny dear…" Inko said.
"It is a little funny, imagining this little old man utterly destroying All Might in a fight!"
"Much as I hate to agree with him, it is a little funny. Kinda. Still not that funny…" Mitsuki said, as if agreeing with that man was as painful as pulling a very deep splinter from her foot, (and as if she hadn't been laughing almost as hard).
Inko turned to Gran Torino. "Maybe you could tell us more about your own hero career. Why did you want to become a hero? Did you want to protect the innocent? Were you inspired by a hero who saved you?
"Did you desire vengeance against the crime that wiped out your family?" All for One said in a long suffering tone.
"No, no and no," Gran Torino said.
"Then what was it?" Inko asked.
"I wanted to be able to use my Quirk when I wanted. Especially since there was something important for me to do that I needed it for," he said.
All for One looked slightly surprised. "I think I like this one…" he said pointing.
"Why am I not surprised…" Nana muttered.
"Hey," Gran Torino said, "Wouldn't you like to hear stories about Nana?"
Wait what?
"Yes. Yes, we would." All For One said.
"That sounds wonderful!" Inko said.
Please no...
"Oh you're going to love to hear this one," Gran said with an evil grin. "It happened when you were very small Inko. She realized that she needed to buy noodles for dinner (she'd failed to notice your dwindling food supply until you were out. Again)."
Oh no. He was going to tell that one.
"She didn't have a babysitter and thought it wouldn't take long so she took you with her. Then there was a villain attack so she set you down to fight. Then when fighting the villain she stubbed her toe and yelled-"
Seeing her imminent peril Nana quickly assessed the situation. She quickly picked up a small spoonful of food and threw it at the evildoer to put a stop to his nefarious storytelling!
Unfortunately, Gran dodged it sent a glob flying back at her! Nana leaned back letting it fly past her. Hers hit Mitsuki Bakugo who had turned to speak to her husband, while Gran's hit All for One's white shirt. Mitsuki whipped her head around and yelled "ALRIGHT WHO THREW THAT? Nana and Gran, responsible adults that they were, immediately pointed at each other.
With an evil smirk, Mitsuki threw a small blob of food at Nana. It splattered in her face. Nana glared but was going to just take it and- Another piece of food hit her. She looked at Gran feigning innocence. Oh it. Is. On. She picked up a piece of meat and threw it at his face. He picked up a piece of fruit and threw it at her. On instinct, she swung her hand out, spun around, using her Quirk to redirect the fruit into Mitsuki Bakugo. The three looked at each other. Mitsuki adopted a sadistic grin. Inko and Masaru shared a glance before quickly getting up and moving to the edge of the room. All For One took off his sport coat, placed it under the table and muttered "When in Rome…"
Gran yelled "FOOD FIGHT!"
In an instant, the battle royale had begun. Mitsuki picked up several morsels and threw them at each of her opponents with precision she learned from years in the school lunchroom. Gran Torino dodged a piece of shrimp, put his foot into a bowl of soup and used his Quirk to spray Nana and Mitsuki. Nana, knowing his Quirk, managed to raise her hands and block the torrent. Mitsuki rose her hands a second too late and got sprayed.
All for One picked up a chicken leg, breathed fire to heat it, ate the meat, then threw the bone at Nana Shimura for a direct hit. He dodged a projectile from Mitsuki Bakugo and caught another. He threw it at Gran Torino which allowed Torino to see Shimura aiming an attack and attack her. All for One then picked up some beans and threw them at Mitsuki Bakugo. They struck true and hit her right in the face.
Gran and Nana seized All for One's focus on Mitsuki to join forces against him, pelting him with their food! Nana began using her telekinesis to send it flying even faster while Gran used his Quirk to kick it at the Dark Emperor of the Underworld at high speed. Mitsuki soon joined in, helping them bombard the supervillain! As the three continued bombarding the evildoer young Katsuki decided that what they were doing looked fun. So, he started tossing his food at Izuku with a scream that sounded like "DAAAAH!".
Unfortunately, their grand alliance could not hold. Gran Torino was the first to break it, swinging around to hit Mitsuki before attacking Nana. Unfortunately, that second of warning was all Nana needed to use her Quirk to deflect his treacherous attacks. Gran Torino picked up a rather large piece of fruit and used his Quirk to blast it at her! She used her Quirk to force it back. For an instant, it lay suspended between the two combatants. Neither would yield in their epic struggle. Nana pushed harder, but Gran responded in kind. They put all of their hearts into it the mighty clash, until, mere seconds after the deadlock began, the fruit exploded, covering the two in fruit chunks.
Meanwhile Izuku got fed up and started throwing his food at Katsuki with a cry that sounded like "SMAAFFF!". All for One rushed over to them.
"Yes!" he cheered. "Use your aggressive feelings boy! Let the hate flow through you!"
Nana ran over. "Don't listen to him Izuku! Fight for justice!"
"Join the dark side Izuku! They-! He glanced over at Inko "They have all the cool powers!"
"Don't listen to him Izuku!"
"Animal Friendship?"
"Imagine using that on a rancor! Or an Acklay!"
"Fair enough, but we have Force Lightening!"
Gran came over. "Forget their dorky yammering and just pelt him Izuku!"
Nana turned to him. "Gran! Stop helping him turn my grandson to the dark side!"
"I don't care about that, I just think he should bury that brat with his dinner for attacking him!"
"You're not helping!"
"Don't care!"
Mitsuki butted in. "You two sure you're not married?"
"AS IF I WOULD EVER MARRY THAT OLD HAG/TROLL!"
They glared at each other again, then glared at Mitsuki, threw a few pieces of food at her before attacking each other.
"Behold unlimited power!" All for One said as he lifted his hands menacingly, then seemed to remember that he couldn't blast them with lightening (with witnesses anyway) and picked up food to throw instead.
Mitsuki noticed that all three of her enemies were close to each other. And distracted. She got an evil grin. "Hey Katsuki, get a load of this!" She filled both hands and hurled their contents at all three at once. They looked up too late to stop their oncoming doom. Katsuki laughed.
On the side Inko and Masaru watched the carnage that was once their dinner. Masaru turned to Inko. "So, you're not going to do anything about this?"
"No, they're not doing any damage to the house aside from a huge mess (which they will be cleaning up. All of them.), they're getting along relatively speaking, and they seem to be having a lot of fun. Also, this is hilarious to watch."
"Even Torino will be cleaning up?"
"You ever notice he's only senile when it lets him mess with people or get out of trouble?"
"Oh. Didn't notice. Still you're taking this remarkably-you're recording this, aren't you?" he said pointing at her phone.
"Oooh yes."
"They're never going to live this one down, are they? Ever?"
"Nope!" She said with a bright smile.