Dragon Ball Z Special 2: Zetsubou e no Hankou!! Nokosareta Chousenshi - Gohan to Trunks
English title: Dragon Ball Z: The History of Trunks
Japanese title: ドラゴンボールＺ・絶望への反抗！！残された超戦士・悟飯とトランク
Alternative titles: Dragon Ball Z: Resist Despair!! The Surviving Fighters - Gohan and Trunks
Type: TV Special
Source: Manga
Episodes: 1
Status: Finished Airing
Aired: Feb 24, 1993
Duration: 48 min
Rating: PG-13 - Teens 13 or older
Studios: Toei Animation
Licensors: Funimation
Genres: Adventure, Drama, Fantasy
Demographics: Shounen

It has been thirteen years since the Androids began their killing rampage and Son Gohan is the only person fighting back. He takes Bulma's son Trunks as a student and even gives his own life to save Trunks's. Now Trunks must figure out a way to change this apocalyptic future. 

(Source: ANN)