Idaten jump: Sparkles of Happiness

This is Fanific of Idaten Jump.
After a whole 2 years Princess of X-Zone Yuki calls Sho and his friends back to X-zone in order to defeat the evil powers which are causing problems in x-zone and their neighboring world.
They will even find out to why only they given the idaten bikes. They get to know about their parent's secret.

What's the answer to the mysteries? What is the secret?

Read the book to find out😉