Story's Challenge

Touhou Z: A New Beginning

During the confrontation with Zamasu, Goku and Vegeta falled from the time machine right as they were escaping the future who was about to be destroyed. However instead of being erased they were transported in another world.

Gensokyo.

After waking up Goku and Vegeta were wondering where they were. So they look aroud and meet many of the resident who were interested in the two alien from the outside world.

After that, Goku and Vegeta will have to make a choice. Either go back to their own world or stay here and make a new life.

As for the pairing.

Goku x Kaguya

Vegeta x Mokou

The reason? Kaguya became interested in Goku because he was not intranced by her beauty, Also because his personality was pure and innocent. something that it's very rare today.

Mokou wanted to know more about Vegeta because he was a bit like her. They both lost their family at young age. they both want to have revenge on someone. And he was loner by nature.

Not only that, But since Goku and Vegeta are rival like Kaguya and Mokou, I think that would be hilarious to see them together. I can already picture Kaguya and Mokou arguing on which of their lover is the strongest.

And before you ask about Chichi and Bulma...They dead in this Story.

When Goku Black came to the present. Chichi was with the others, to spite on Goku, Black decide to kill Chichi before he was send back to the Future. Bulma was killed by Zamasu after he fuse with Black. Which give the two Saiyan more reason to take them down.

After that it's up to you. Whetever the Touhou characters learn to use Ki or not is your decision. To be honest, It wouldn't be the first time that Goku and Vegeta train someone in that regard...Not that it's a bad thing mind you.

Also since Touhou don't have a Saga or story arc. You can either bring them all in the outside world so that they can live adventure. Or you can expend Gensokyo and make new characters.