How did dan and his friends find bakugan?

Answer 1

When Alice's grandfather Michael teleported to Vestroia, homeworld of the Bakugan, a link between Earth and Vestroia. If you've seen the first episode of bakugan, you heard the story in the intro. This is what Dan said:

" I know this is gonna sound weird, but one day, my whole world changed. You see, cards started dropping from the sky, coming down like rain. At first, we didn't know where they were all coming from or who sent them. We only knew they were more than just ordinary playing cards, and it was happening all around the world. In the north......in the south......they landed everywhere! Together with my new online friends from around the world, we invented a cool new game we called...Bakugan. That's when the power of the cards was revealed. Each one held its own battling beast which came to life when you threw it down. The battles were intense, and if you chose the wrong card you lost it and the beast inside. But that's only half the story. Another even bigger battle was taking place in a parallel universe called Vestroia."