The whole multiverse is once again on the verge of collapsing. Goku who stays at Uub's village for years and as the strongest and most powerful mortal in universe 7, fetched his sons, and friends to join the multiverse heroes for a battle. Chichi won't allow Goten to join the force as he just turned 21 and he is about to finish his thesis but out of desperation to save the multiverse, he left with a heavy heart - leaving Chichi in pain.
P.S.
I don't own any of the characters in Dragon Ball. Credits all belong to Akira Toriyama.