Hideki Goh

A young race car driver that died when rescuing a little boy and a dog from falling rubble caused by a fight between Takkong and Zazahn. His valiant sacrifice is noted by everyone, even his friends and the new defense force MAT (Monster Attack Team), but an unseen being also took notice. Looking over him was Ultraman Jack, who was so touched by his heroics that he decided to merge his own life-force with Hideki's, thus bringing him back to life (just like the original Ultraman did with Shin Hayata), much to everyone's astonishment. MAT asked him to join the team, to which he agreed, especially since, in this frightening new "Age of Monsters", the Earth would need a savior. In times of crisis, Hideki Go would raise his right arm, and by force of will, transform into Ultraman Jack to fight monsters.

The Return of Ultraman
Pending

Ultraman Ace
Although not appearing in the series, an impostor of Goh Hideki, disguised by Alien Achira in Episode 10 in Ultraman Ace.

Ultraman Taro
In episodes 33 & 34 he returns with Shin Hayata, Dan Moroboshi, & Seiji Hokuto. The group gathered for a celebrative barbecue with Taro and Zoffy in human hosts. Unfortunately the Ultra Brothers' celebration was interrupted by Alien Temperor. For a time the Ultras switched hosts. Eventually they transformed and defeated the evil invader and returned home.

Utraman Leo
Hideki Goh appeared on this sereis to fix Dan Moroboshi' s Ultra Eye and give him a new capsule monster Sevengar. When Ultraman Jack was flying he got stopped by Ashuran ! the two quickly went into battle but Ultraman Jack accidentally brought him to Earth. After Ashuran was defeated Hideki Goh went back to Nebula M78

Ultraman Mebius and the Ultra Brothers
In 1986, Ultraman Jack and the Ultra Brothers chase Yapool to Earth, after which they imprison the monster under the ocean near Kobe City. In the process, the Ultra Brothers lost their powers and were forced to live as human beings. Hideki Goh, in particular, returns to the car-racing industry and works as a racing instructor. He appears to own a racing academy. 20 years later, in 2006, Go and the other Ultra Brothers transform again in order to help Ultraman Mebius. Eventually, the Ultra Brothers regain their powers and returned to normal when Zoffy and Ultraman Taro came to help them in the last battle with the Ultimate Super Beast.

Ultraman Mebius
Hideki Go appeared in episode 45 of the Ultraman Mebius series. He meets Mirai when he was depressed by how the public turned against his friends for being unwilling hostages. Hideki/Jack convinced him to not give up his faith in humanity. When Deathrem attempted to destroy Crew GUYS, Hideki transformed and protected them for Mebius. In the episode, he was usually seen driving a jeep. At the end of the episode, he was speaking telepathically to Ikaruga George.

Great Decisive Battle! The Super 8 Ultra Brothers
Hideki Goh reappeared in Great Decisive Battle! The Super 8 Ultra Brothers movie as Ultraman Jack's human form. Along with the other Ultra Brothers hosts and human forms, Hideki was a normal human being with a wife and daughter running an Car Repair Garage. Good friends with the other three Ultra Brothers' hosts he was close with Daigo, Gamu and Asuka. Sometime into the movie after meeting up with Hayata, Dan, Goh, Hokuto, their families and Daigo as well as Asuke and Gamu at Dan's restaurant, the seven men take a walk together. As they do, a mysterious cloaked being knocks out a person driving a truck, making it head right towards a group of kids. Before the truck reached them, however, Hayata, Dan, Goh, and Hokoto rescue the children and stop the truck with amazing speed. The mysterious being, however, laughs at this and vanishes. Daigo begins to think again that they could be actually Ultramen, but once again dismisses it. A day later, when King Pandon attacks the city during his Fight with Mebius, Goh's wife is injured while protecting an old man from falling rubble, leaving her in a coma and Goh emotionally crushed. Later on, after hearing Rena's message on the Radio, Goh goes with the other Ultra Brothers and encourages Daigo, who turns into his Ultra form, along with Asuka and Gamu. When the three seemed to be losing, by the words of their wives and the thoughts of their loved ones, Goh and the other Ultra brothers transform and revive the petrified Mebius. The eight Ultras proceeded to destroy Giga Chimera. Later, when the dark wizard appeared, Goh and the other Ultras went into Glitter Mode and destroyed the entity of minus energy. Afterwards, in human form, the group are met by their families who tell Go that his wife was out of critical condition and had awoken. After Mebius had returned home, and Daigo, Asuke and Gamu had achieved their dreams, the seven heroes and their families head off to the Nebula M78.

Ultraman Saga
Hideki appeared in the Ultraman Saga movie with Dan, Seiji, Hayata and Gen, each serving as the mouth piece for their Ultra counterpart. They met in the land of light when Seven/Dan noticed that Zero had just moved to another universe. While the questioned why he would do that they also noted that something was going around different universes and taking monsters, even some from the Monster Graveyard. They noted that it was a powerful source of minus energy and that unfortunately they could only monitor a few of the countless alternate Space-Time zones.

In a deleted scene, Jack and the other Ultra brothers would fly to the alternate Earth to assist Ultraman Saga against Alien Bat's monster weapons. Jack would face his old enemy Black King again and defeat him with the Ultra Lance.

Transformation
Will Power: Hideki Goh can transform into Ultraman Jack by sheer will, as long as Jack allows him to. This is signified when Goh waves or holds one of his arms above his body and Ultraman Jack is activated.