I just bought this DVD and it was amazing! You have to see it!
This is the story of Chibi Miria Trunks. The story starts out, with Gohan running home. Krillian tells him Goku is dead, he had died from a heart virus.
The scene shifts to thirteen years later. Two killer androids, Juunanagou (Android 17), and his twin sister Juuhachigou (Android 18) arrive. They kill Piccolo, Vageta, Tien, Yamcha and Krillian.
Trunks is in a car with his mother, and he flies out of it, after hearing that another town, Pepertown to be exact, was being destroyed. He arrives their and sees the town in ruins. The androids destroyed everyone. Their is a comic relief scene where 18 tries on a bunch of clothes, and she gets upset at her brother for destroying the store with clothes inside. Suddenly a man arrives, wearing Goku's gi. The man turns out to be Gohan, and he agrees to train Trunks harder than ever.
Well at an amusement park the androids go and play on the rides, saying how fun it is (the American dialogue is funny. 18 says "Pick a steed, cowboy" to 17 when they go on the merry-go-round). Trunks and Gohan show up and Gohan fights 17. When 18 interferes, Trunks begins to fight her. She almost kills him, but Gohan saves him. They run for cover, but 18 Blows up a large area of the park, and severely injures Gohan and Trunks. Gohan gives Trunks the last sensu. Trunks brings him home. Oh by the way, Gohan lost his arm in the explosion.
The androids show up again, after Trunks' training. Gohan says that he wants to go alone, and Trunks begs to come. Gohan agrees, but then knocks Trunks out and flies of to his doom. Gohan fights the androids, but he can't defeat them. They kill him, and leave him for dead. Trunks wakes up and goes to check on Gohan. He runs up, crying, "Son Gohan, Son Gohan, Son Gohan," he screams and goes SSJ.
Three years later Trunks goes against the androids again, and nearly dies. His mom somehow saves him. She nurses him back to health and he uses the time machine to goes into the past. The credits role and scenes from the show of him killing Freiza are shown
Dragon Ball Z