Gunpei Ishihara

"Dash Dynamic!! Go-on Black!"

Gunpei Ishihara (石原 軍平) is Go-on Black (ゴーオンブラック) of the Go-Ongers. Nicknamed the "Chaser," he is a former police officer with excellent marksmanship and a passion for justice who sees the Go-Ongers de-transform.

Go-Onger
His code name as a police officer was "Handsome Detective," and he passed himself off as such until his former partner revealed that Gunpei had never been a detective. He decides he wants to help and quits the police force (because the police had considered the Gaiark out of their jurisdiction) and tells the Go-onger this but is refused. Gunpei decided that the police had lost their sense of justice. He then decides the Go-Ongers are unfit to be heroes and kidnaps BOMPER while stealing the Engines. BOMPER explains to him how the three were chosen and eventually decides to help the Go-Ongers by returning the Engine Casts to them the moment they need it most. Bomper decides to make him the fifth Go-Onger, Go-OnBlack, alongside Hanto Jou who becomes the fourth Go-Onger, Go-On Green. Gunpei does not like sweets, but after he tasted a special cake Saki Rouyama had made, he found it delicious and eagerly accepted a slice. After the final battle, Gunpei returns to the police force and finally becomes a detective.

Gunpei initially belittles Sosuke Esumi, Renn Kousaka, and Saki for being "just" kids and claims that he is "a man more qualified to be a Go-onger." Though Kenji Ebisawa, the actor who portrays Gunpei, is indeed older than Rina Aizawa, who plays Saki (and is one of three cast members under the age of 20; Masahiro Usui and Yumi Sugimoto are the other two), he is, ironically, younger than both Yasuhisa Furuhara and Shinwa Kataoka, the actors who play Sosuke and Renn respectively.

After transforming into Go-on Black, Gunpei says, "Dash Dynamic!! Go-on Black" (ダッシュ豪快！！ゴーオンブラック). With the Cowl Laser (カウルレーザー) he can perform the Laser High-beam (レーザーハイビーム).

Encountering the Gekiranger, the Go-Ongers lose the Engine Souls to the Gaiark and Meka. With Ran Uzaki and Ken Hisatsu's help, Gunpei and Saki manage to gain Geki. With Engine-Ken, a new type of Geki fighting fist, Gunpei was able to access his beast spirit (which turned out to be Gunpherd). With this he performs Ganga Ganga Dan, where Gunpherd, apart of his Engine Soul, attacks, as a manifestation of will.

Gokaiger
A few years later, Gunpei fought alongside not only his own team, but every single Sentai ranger in existence, against the Empire of Zangyack when it attacked the Earth in the Great Legend War. After fighting against hundreds of Gormin and their Zgormin commanders. AkaRenger noticed the fleet moving towards them, he gathered all the Rangers together and gave them the order to sacrifice their powers to wipe out the first invasion's armada.

Super Hero Taisen
Gunpei, alongside his team (the Go-On Wings were absent), among the majority of the Super Sentai heroes, was caught up in the "Super Hero Taisen" incident which eventually resulted in the Super Sentai teams and Kamen Riders joining forces to defeat both Dai-Zangyack and Dai-Shocker.

Super Sentai Battle: Ranger Cross
Go-On Black appears with his team in Super Sentai Battle: Ranger Cross.

Engines

 * Engine Gunpherd
 * Gunpherd Soul
 * Gunpherd Cast
 * Engine Carrigator
 * Carrigator Soul
 * Carrigator cast

Arsenal

 * Shift Changer
 * Change Soul
 * Mantan Gun
 * Cowl Laser
 * Handle Blaster
 * Blaster Soul

Ranger Key
The Go-On Black Ranger Key (ゴーオンブラックレンジャーキー) is Gunpei Ishihara's personal Ranger Key and what became of his powers after he along with the rest of the 34 Super Sentai sacrificed their powers to end the Great Legend War.

This key along with the majority of the Ranger Keys were collected by the Red Pirates and later used by the Gokaigers. The Go-On Black Ranger Key was mainly used by Ahim de Famille (Gokai Pink), who used it to fight as Go-On Black.
 * Alongside Joe (AbareBlack) and Luka (NinjaBlack) as part of a all-black change in their fight against Action Commander Salamandam.
 * When the Gokaigers became the Go-Ongers while fighting against Gormin while Marvelous was absent.
 * When the Gokaigers became the Go-Ongers while fighting a Zangyack force led by Insarn and Barizorg.
 * When the Gokaigers became the Go-Ongers while fighting Action Commander Zaggai.
 * When the Gokaigers became the Go-Ongers in their fight with Pollution President Babatcheed.

After Zangyack were finally defeated, the Gokaigers gave the Ranger Keys back to their rightful owners. It is presumed that Gunpei received his key and became Go-On Black once more.

Portrayal
Gunpei Ishihara is portrayed by Kenji Ebisawa (海老澤 健次). As Go-On Black, his suit actor was Yasuhiko Imai (今井 康彦).

Dub names
In the Korean dub of Go-Onger entitled Power Rangers Engine Force, which aired in South Korea, Gunpei is known as Alex, while his Ranger designation is Engine Black.