After Goku was killed, he went to the next dimension and found out that a guy named King Ki could help make him stronger. So Goku began his quest to King Ki's place, he had to cross snake way, which took him almost the whole year to cross!! When he got to King Ki's planet, he had to overcome the heavy gravity by catching Bubbles- a monkey that was King Ki's pet- and hitting Gregory- a cricket that is friends with King Ki- on the head with a mallet. After all that, he trained the rest of the time with King Ki and perfecting the Kao-can attack. Goku was becoming very strong and he had in fact beat King Ki in every task he was taught.
In the mean time, Goku's friends were all training hard too. Everyone- except Hanna, Piccolo, and Gohan- was on Kame's lookout training for the battle in 1 year.
Hanna was also training herself, in the forest, like she always did when all of her chores were done. She would use an attack that she called the mirror double. She would make copies of herself and fight the copies. This way she always had a good battle with a power equal to hers.
On the opposite side of the forest, Gohan was being trained. He first had to survive a survival test and then he had to fight Piccolo directly. For the whole year Gohan trained with Piccolo, he was a handful for Piccolo since he got a good look at the full moon- twice in fact. Hanna, on the other hand, was able to avoid the full moon's light.
Oh, no! The saiyins have arrived!! Goku has been wished back and is on his way back to help the fight, but what's this? If Goku doesn't hurry the he'll be too late!! Hurry up Goku, they're all counting on you!!!