"Keep your left up, Goku! And Pikkon, for Grand's sake, just kick him in the ribs when he does that!" King Kai shouted encouragement and criticism alike up at the two warriors sparring dozens of feet in the air. He realized it was largely pointless. Both fighters were several orders of magnitude more powerful than him at that point. Which… irked.
"King Kai, don't encourage him," Goku whined back. Pikkon really didn't need any more reasons to kick him in the ribs. The West Galaxy warrior didn't exactly take it easy when the two of them trained together.
Pikkon smiled at the comment and slid back through the air to shoot a ki blast at Goku, who deflected it easily enough. It crashed and exploded on some part of the empty field they were training in. Neither paid much attention to that part. King Kai was just grateful that the Other World seemed to have a high tolerance for the rampant destruction of its landscape.
Pikkon was a short distance above Goku, and Goku was about to rush him when Pikkon crossed his arms and quirked an eye at something over Goku's shoulder. "Is that human watching you a friend of yours?"
"Hm?" Goku twisted partially out of his fighting stance to turn around.
There was someone watching them, standing a short ways off from King Kai. It was a stocky, well-muscled man with dark hair and moustache, small eyes, and a soft expression. He wore a Chinese-style martial arts uniform. "He looks familiar…" Goku said.
Goku did know him. In his mind, he saw him wrinkled and stooped with age and bald beneath a green cap. But then he smiled gently up at them, and Goku's joy split his face into a grin. "Grandpa?"
Pikkon flinched at the sudden rush of air as Goku bolted down and swooped the man up into his hands, holding him up as one might a child. "Grandpa! Grandpa Gohan! Pikkon, it's Grandpa Gohan!"
"Okay."
"Yes, Goku. Hello again my boy." Gohan smiled widely. "You have certainly gotten taller." Goku was holding him under the arms, and Gohan's feet were embarrassingly high off the ground.
"I know, right? I got even taller than you, Grandpa." As if this was an accomplishment.
Goku abruptly set Gohan back down, and only his martial arts instincts kept him from falling off his feet.
"And I've gotten a lot better at the Kamehameha, too! Watch! Kamehame-HA!" The blue ki wave blasted off into the atmosphere. It probably wouldn't land anywhere important.
"Yes, Goku, I am so prou-"
"And I trained with Master Roshi lots, and then I got married and met Vegeta and went to Namek and fought lots of really strong guys, Grandpa! And this is my friend, Pikkon!"
Goku rushed back up to Pikkon, grabbed him by the wrist, and yanked him back down to be presented before his grandfather before Pikkon even registered that Goku had moved. If he had ever moved that fast during one of their fights, Pikkon wouldn't have stood a chance.
"It is very nice to meet you, Pikk-"
"Pikkon's really strong too. You'll like him. And that's King Kai. He taught me the Spirit Bomb and used to live on a tiny planet that I accidentally blew up with Cell, and that's how I died the second time!"
At this point, Gohan gave up trying to get a word in edgewise and just smiled patiently at his grandson.
"And I learned the Instant Transmission, look!" Goku put two fingers to his forehead and disappeared only to reappear further out in the field. "See Grandpa!" Goku shouted and waved. Gohan waved back indulgently.
"I get the feeling we're not getting anything else done today," Pikkon lamented as King Kai shuffled up to them.
"I can also go Super Saiyan!" Goku shouted at them from across the field and burst into gold and green, "and stay in a hand stand for a really long time." He demonstrated. "Like, four minutes, probably."
King Kai shook his head. "So, you're the unfortunate guy that raised Goku, huh?"
Gohan chuckled. "Not unfortunate at all. It was my greatest honor."
"Hey Grandpa! Look how fast I can run!"
"If you say so," King Kai grumbled.
"Grandpa, are you watching?!"
Many, many hours later, Goku finally exhausted himself. King Kai and Grandpa Gohan had long since taken a seat in some lounge chairs that King Kai conjured up, and Pikkon had left around the time of Goku's third super Saiyan demonstration. Goku had finally fallen asleep with his knees on the ground and his head in his grandfather's lap. His hair was sticking out at all angles, and Gohan gently patted his boy's hair out of his face.
"Goku as a kid, huh? That must've been exhausting."
"It was certainly… engaging," Gohan supplied tactfully. "He was quite a handful."
"I meant because he's a moron. It must've been a nightmare to teach him to read."
"He's not a moron," Gohan defended. "He's just not always on the same page everyone else is on."
"I'll bet."
"And some of that is, I suppose, my fault. I kept him so isolated up in those mountains, nothing but bears and martial arts."
"That explains so much about him."
Gohan petted Goku's wild hair again, and Goku sighed and hunched further over Gohan's lap. "He always understood things so simply. I told him I was his grandfather, so I was. I told him Mount Paizo was home, so it was. I told him not to look at the full moon. So he didn't. Not on purpose, anyway."
"But, come on, when did you realize he wasn't from Earth?"
"Well, the spaceship I found him crashed in was a bit of hint."
King Kai snorted in amusement. "Yeah, I guess it would be."
"But… I always knew he was going to be extraordinary."
King Kai paused for a moment. Then, "How much of his life after you died do you actually know?"
"Bits and pieces. Rumors, both from Heaven and Hell. I met a Namekian named Guru a while back. And my friend Baba helped, when she could."
"Well, he was definitely extraordinary."
"Oh no. He still has so much more to do."