Jaco the Galactic Patrolman

Jaco the Galactic Patrolman (銀河パトロールジャコ, GINGA PATROL JAKO) is a series by Akira Toriyama, legendary mangaka of Dragon Ball, and a has a confirmed tie-in to Dragon Ball.

Plot
Jaco, a Galactic Patrolman sent to Earth to protect it from an evil alien attack, crash lands on Earth. He meets the retired scientist Omori who offers to try and fix his spaceship. The next day, government policeman Katayude informs Omori that he does not have the right to live on the island and has to vacate it in one week or be arrested. Jaco learns that Omori has continued his research on time travel in order to save his deceased wife and assistants, but is only able to temporary speed up how the user experiences time, giving the illusion of stopped time (Not actual time travel according to Jaco, which is against intergalactic law.) Omori repairs the spaceship, but realizes that it needs a very expensive metal as fuel.

During a trip to the capital for supplies, Jaco saves a young woman from thugs, but also unknowingly attacks the police, becoming a wanted man. The woman, Tights, decides to join Jaco and Omori on the island and buys a small amount of the expensive metal with the money she was given for agreeing to act as a body double for a pop star in an upcoming dangerous rocket launch publicity stunt. Although not enough to make the trip home, it will allow Jaco to call for help. However, he breaks the ship's radio antennae while showing off.

Katayude sees a news report on Jaco's crime in the capital and realizes he saw the suspect on Omori's island. He arrives with a team the next day to arrest Jaco. During the confrontation, the rocket holding Tights malfunctions and starts falling to Earth. After quickly subduing the government police, Jaco and Omori use Omori's incomplete time machine to give themselves enough time to save Tights. In thanks for preventing a catastrophe, Katayude not only promises to keep Jaco's whereabouts secret, but also allows Omori to stay on the island.

On the day the invading evil alien is suppose to land, Jaco does not see the ship land thanks to Tights and so comes to the conclusion that the Earth is saved. However, the alien did in fact land and is taken in by Son Gohan who gives him the name Son Goku. Thinking to use parts of the ship in order to make the money needed for fuel, the trio call over Tights' father who happens to be Dr. Briefs, a scientific genius and richest man in the world. But it is her little sister, Bulma, who fixes the antennae and informs everyone that the expensive metal is not the ship's power source but is only used to store energy, the similar and much cheaper copper would do the same job. Jaco returns home and Omori buys the island with money from Dr. Briefs. Years later, Katayude has moved to the island as well, Tights has become a science fiction writer, Jaco has found a girlfriend and occasionally visits, and Bulma stopped by having just started out on a journey to gather seven wish-granting balls.