"Chapter 1" is the 1st chapter of the Dragon Ball: That Time I Got Reincarnated as Yamcha manga.
In the real world Japan, a student is asking others if they are interested in seeing a new Dragon Ball attraction including an ordinary boy who agrees to go but asks if there will also be girls there as well. He says that would it would be great to meet a fellow Dragon Ball fan who was a girl and proclaims that yesterday he won a Dragon Ball Z: Dokkan Battle battle event with Yamcha proving useless which impresses his friend.
Whilst crossing a bridge they spot an attractive girl and the boy runs over to have a closer look but trips down the steps and loses consciousness. He reawakens in the Dragon World as Yamcha in the Diablo Desert. The boy is startled by his setting and clothing and when looking in the mirror that was on his person he realizes that he is now Yamcha.
At first he believes it to be part of the attraction that his friend had mentioned but doesn't recall even going to it and comes to the conclusion that he died chasing after Panties and has now been reincarnated as Yamcha in another world. He then expresses disappointment that he came back as Yamcha as opposed to Goku or Vegeta but is interrupted by Oolong and then see's a sleeping Puar, Goku and Bulma who he comments on being the cutest girl he has ever seen. The boy begins to get excited upon realizing that Yamcha and Bulma eventually became boyfriend and girlfriend but vows not to cheat on her like the original Yamcha did.
Goku awakens and realizes he has lost his tail and the boy finds amusement that events are playing out just as they did in the Dragon Ball anime. He says goodbye to Goku, who desires to go train with Master Roshi and as he is about to head off to West City with Bulma he suddenly recalls Yamcha's death at the hands of the Saibamen. He wonders if he should just give up on fighting now as Yamcha never had many victories anyway but stops himself and realizes that it is his chance to change things and turn Yamcha into the strongest Eartling. He apologizes to Bulma and asks her to wait for him and then heads off with Goku on the Flying Nimbus to Kame House to receive training from Master Roshi.
Many years pass by until the day that the Saiyans finally arrive on Earth. Yamcha stands firm in front of the threat of Vegeta, Nappa and the six Saibamen. Vegeta suggests to make a game out of the opportunity by having each of the Earth Warriors battle one on one against the Saibamen but Yamcha claims that he will take all six of them on by himself.
The Saibamen leap towards Yamcha but he promptly kills one with a single blow which unnerves the five remaining Saibamen but after Vegeta threatens that they will all die if they do not beat Yamcha they all leap on top of Yamcha and use the Saibaman Bomb to the horror of his allies.
However, this time around Yamcha survives the explosion with only minor scratches on his body. It is then revealed that Yamcha took advantage of knowing future events and at some point visited the Grand Elder Guru on Namek who unlocked his potential.
- Yamcha (Reincarnated) vs. Six Saibamen
- The "Dragon Ball The Real" attraction at UMJ that is mentioned in the chapter would seem to be based on Dragon Ball Z: The Real 4-D attraction that is located at USJ (Universal Studios Japan).