Flying Nimbus and Sparring

Bulma watched Master Roshi pass straight through the Flying Nimbus and land on the ground with a thud, flipping over like a turtle and clutching his backside. She could not help covering her stomach and bursting into laughter. He-El, standing nearby, smiled as well. Goku looked curiously at the Flying Nimbus. "Master Roshi... are you all right?" Turtle hurried over to Master Roshi, helping him up as he asked worriedly, "What happened?" "How strange!" Master Roshi was confused too. He actually could not sit on the Flying Nimbus.