Goten and Trunks are currently fighting at the World Tournament. They clash as they punch each other in the other's cheek, then separate.
Trunks: (Thinking) Dang it, I can't get him out of the ring! I guess that's what I should expect from the son of Kakarot! (out loud) Okay, how about we get a little spicier? Rah!
Trunks fires a ki blast, which Goten jumps over. Cut to Goku watching from above.
Goku: Oh hey, Gohan, you taught him how to dodge. That's great.
The ki blast travels towards the audience. Cut to that viewing area where Goku, Gohan (dressed as The Great Saiyaman), Videl, Krillin, Piccolo, Vegeta, and Android 18 are all watching.
Gohan: TRUNKS, PULL IT UP!
Trunks flicks his fingers sideways as the ki blast follows Goten, who dodges again. Goten then suddenly rushes towards Trunks, charging a ki blast. Trunks gets ready to counter until Goten suddenly jumps over Trunks. Trunks is confused until his own ki blast hits him in the face. Goku gets wide-eyed as he remembers doing the same to Piccolo.
Trunks: Ouch! Not bad! But-
Before Trunks finishes his sentence, Goten forms a ki blast in his fist and punches Trunks in the back. He then jumps and kicks Trunks' head down.
Trunks: Wait a minute! Goten! We agreed to not use Super Saiyan! I felt your power spike!
Goten: I don't know what you mean...
Goten shrugs while Gohan smirks knowing what is happening. Trunks gets up and tries to punch Goten, but Goten dodges. Goten jumps back and starts to charge ki in his hands.
Goten: KAME... KAMEEEE...
Trunks: Dude, you're not even saying it right. It's "KameHame"-
Goten then suddenly rushes forward while still charging the ki wave.
Goten: HA!
Goten shoots the beam in Trunks' face. For a split second, he turns Super Saiyan. Trunks gets launched back almost getting eliminated via ring out, but he stops himself. Only to meet with a ki blast face first. This doesn't do anything besides piss Trunks.
Trunks: Wait, even if you say it wrong it still works? Then why say it at all?
Gohan: Because it sounds cool!
Trunks: Fine… If you don't want to play by the rules…
Trunks turns Super Saiyan and starts charging at Goten. Goten gets ready to counter, but he suddenly sidesteps, which Trunks wasn't expecting, as he once again almost gets ringed out. Trunks then tries firing a volley of ki blasts at Goten who dodges all of them. He then clashes with Trunks with both either guarding or dodging the other attacks. Whenever there's a chance one lands an attack, it leaves a mark with Goten using Super Saiyan every time he does, but only for a split second.
Goku: No way! They're both Super Saiyans!? Incredible!
Goten then suddenly backflips and then charges forward with a punch.
Goten: Rock!
It lands and hits Trunks' nose. He then sticks his index and middle fingers out
Goten: Scissors!
He hits Trunks in his eyes, briefly blinding him. He then sticks out his palm.
Goten: Paper!
This launches Trunks towards the edge of the ring again, almost a ring out, but Trunks recollects himself. Goku looks on with pride.
Goku: WOW! Gohan, did you teach him that?!
Gohan: Nope! We went to train with Master Roshi for a bit and he taught us some of his moves. Although I did teach him the Super Saiyan trick.
Trunks: Ugh! Now you're just playing dirty!
Goten then uses Taunts by sticking his tongue out. Trunks fell for the Taunt! He then starts to power up. Goten smirks knowing full well what's about to happen. Trunks' muscles then bulge as his hair grows bigger, spikier, and spreads in different directions. His face then gets slightly red.
Trunks: THAT'S ENOUGH! I'M ENDING THIS NOW!
Trunks then flies up and extends his arms charging a move that references Vegeta's Final Flash. Vegeta looks in shock at the imitation of his move. Goten responds by finally going Super Saiyan and charging ki in his fists. As Trunks fires his beam, Goten flies toward it and holds it back, but he's slowly getting pushed back.
Goten: (thinking) Ok I knew he was strong, but I wasn't expecting this! I need to end this now!
Goten then expands the ki in his hand to make a wall of ki. He flies over Trunks' beam. Before Trunks could realize what was about to happen, Goten fires a point-blank ki blast in his face. While this does cause Trunks to stop firing his ki blast, he doesn't take any damage from the attack. He tries to clash with Goten, but due to the disadvantage of speed, Goten dodges every attack until Trunks gets too tired to continue. Goten then simply gut punches Trunks, ending the fight. Trunks powers down and lands face-first in the ring, unconscious.
World Tournament Announcer: Ladies and Gentlemen! We have a winner! The new Junior division world champion is Son Goten!
Vegeta: Tsh! He blew it! Using up all his power like that!
Gohan: Yep! Trunks may have been stronger, but I taught Goten to beat his opponents in other ways!
Goku: Amazing! He was conserving his power while making Trunks use all of his!
Gohan: What good is being strong when you can't hit your opponent?
Goku: But why teach him to only briefly use Super Saiyan? Why didn't you let him master it?
Gohan: I tried to help him, but due to him being so young it was hard for him to contain all that power 24/7. So until he learns to master it, I figured him conserving his energy was best.
Goku: Wow! You're a great teacher, Gohan!
Gohan: I was just thinking of what made you a good fighter, Dad. You're a good teacher.
Yeah kinda short, but at least it's something.
I think it's fair for Goten to go to Master Roshi to train. Chi-Chi would know and would definitely tell Gohan. Hope you enjoyed!