Goku was right now watching TV with Izuku as he was watching that All Might had just beaten Texas Chainsaw. But something got Goku's attention he felt a 2 tremendous powers far away but he was able to sense them.

Goku - Izuku stay here I'll be back in a bit.

Izuku - Ok Dad. Is something wrong?

Goku - I don't know but tell your mom I'll be back in a bit.

He left with instant transmission and this caused Izuku to worry more as he saw the face his father was making.

(Somewhere far from Japan)

AFO - You destroyed my entire work after decades of planning and creating. You will pay for everything All Might.

All Might - I won't let you terrorized innocent people anymore! THIS IS THE END! DETROIT.....

Before All Might could finish he felt a sharp pain in the left side of his stomach and he noticed a giant black and red tendril inside his stomach.

AFO - You let your guard down. Now perish and wither away!

Before he could release another attack it was stopped causing both All Might and AFO to look in front of them to see someone hold out AFO hand.

??? - Looks like you need some help All Might.

All Might saw and recognized the man as Son Goku the hero from Japan.

Goku kicked AFO away and he gave a hand to All Might.

Goku - You okay?

All Might - How did you get here I thought you lived in Japan?

Goku - I sensed your energy and used my instant transmission technique to get here. But that's not important. Let me take care of this guy.

All Might - Wait he's too powerful!

Goku - I should be able to take him on don't worry.

He quickly flew towards AFO as he got off the ground and looked up at Goku.

Goku - Your fighting me now!

AFO tried to use his quirk to attack him but Goku dodged every attack and when he got close enough he punched him right in the jaw. Goku then delivered a giant kick to his gut pushing him back far. AFO quickly recovered and waited to use his quirk against Goku.

Goku sped to AFO but was pushed away with a giant air pressure and he crashed into many destroyed buildings.

AFO - Fool do you actually think you can defeat me?

Out of nowhere AFO was blasted to the ground and Goku was shown flying in the air as he prepared a giant Kamehameha.

Goku - This should finish it. KA..ME...HA..ME...

Before he could shoot the blast AFO used a blinding quirk as it blinded Goku and All Might and both covered their eyes as AFO escaped.

Goku - Damn he got away. Huh oh yeah All Might let me help you out.

Goku took All Might to the hospital and waited to hear results of his injury and met his sidekick Sir Nighteye, Gran Torino, Recovery Girl and Nezu. He introduced himself and All Might came out bandages and injured as he was sweating and holding on the wall.

Nighteye - STOP IF YOU KEEP GOING YOU WILL FACE OFF AGAINST A VILLAIN AND DIE A AThis TERRIBLE AND HORRIFYING DEATH!!

Goku - No he won't. I promise I'll protect him and make sure when the time is right he chooses a successor.

All Might - How did you hear that?

Goku - I have enhanced hearing. But All Might I'll help you find a successor and make sure you won't die a terrible death.

All Might then formed a small smile as Goku helped him out of the hospital and used some of his energy to try to heal him but he could only heal half of his damage.

All Might - Thank You I am forever in your debt.

Goku - No need just helping someone in need is part of being a hero right.

This caused All Might to laugh proudly as it was the beginning of a great friendship.

(Timeskip)

Years passed by and All Might time as the symbol of peace had to be short and thanks to Goku he was able to do it. Goku would often have a small timer on his phone and when he was done after 3 hours he checks up on All Might making sure he isn't using his power much. Thanks to him All Might time limit as the symbol of peace was half a day. 

Right now we see our Saiyan Hero training Izuku as he was dodging every blow from Izuku.

Goku - Come on Izuku you can do better.

Izuku kept trying to land a blow but he failed when Goku sweep kicked him and was about to land the finishing blow. But he stopped and gave his hand to Izuku and he accepted.

Goku - Not bad you have gotten way better and more faster with your strikes but you have to remember to focus on my energy. Don't try to see what I'm gonna do feel it and counter.

Izuku - Right.

Goku - You should hurry and shower because not everyone in school will want you smelly.

Izuku laughed as he showered and started eating breakfast and Goku noticed Katsuki coming towards the house and Izuku felt it as well.

Izuku - Looks like Kacchan is here well dad I got to go.

Goku - Okay Izuku be careful and remember if anything happens to call me.

He left and Goku got a call from All Might and asked him for some help looking for a sludge villain. He smiled and got his gi and ran to the door and started flying out as he was trying to find the villain but he realized he never met the villain nor knows how his energy felt like. Goku had t find him the old fashion way. 

Goku - All Might you owe me big time. Your gonna make me late for lunch.