its specially gohan centric movie .i think the plot is pan got kidnapped by them & piccolo got badly hurt or also got kidnapped tring to save pan and gohan caught the wind of it and he went to rescue them. & i think we might get a glimps of his true hidden power in this movie & implement that in the return of the anime. just like he told in dbs ep 90 where he explained he would have a new transformation in a different method than goku & vegeta..