Don Dogoier

"Gokai Green!"

Don Dogoier (ドン･ドッゴイヤー, Don Doggoiyā), better known in the crew as "Doctor" (博士, Hakase) is Gokai Green of the Gokaigers.

Biography
A man with a overly-cautious set of mind that has an alarmist attitude. He is a pacifist who causes trouble because he wants to avoid fighting. He met the Gokaigers when Luka disguised herself to convinced Don to fix the immobile Gokai Galleon, which had been knocked out of working order after a fight with Zangyack forces (not in those words though). However, Don had wanted posters of the then-three-man Gokaiger team nailed to the doorway of his humble shack and ran out on Luka. However, Don was not one to go back on his word and scaled up the Gokai Galleon by himself, and was appauled at the state of things the Gokaigers lived in, which was a place where trash and dirty clothes reigned king. He then tidied things up for them and cooked them a hearty and healthy meal for the crew (all in a matter of seconds). After turning the Gokai Galleon back on, he is given the nickname "Doctor" by Marvelous, "because [he] is always operating".

Unlike the rest of his teammates, who are considered highly dangerous and formidable opponents by the Space Empire Zangyack, Don was considered nothing to worry about and had a measly bounty of just 1000 Zagin. However, it is due to his quick thinking and rare brain power that compliments Marvelous' reckless attitude. Inventions from his calm judgment and clear brain often end up saving the team when they're in trouble. In the series, it was thanks to Don's newfound courage and his resolve to become stronger that allowed the Gokaigers to utilize the powers of both the Magirangers and the Gekirangers.

An act of mercy
When Navi told the Gokaigers they would have to offer help in order to find their next greater power, Don joined with Joe in looking for a good deed to do, resulting in them having to deal with a transvestite after they give back a ring that he dropped on the sidewalk. It was Luka and Ahim who discovered the latest former Sentai hero, which resulted in the Gokaigers gaining the greater power of GoGo-V. That is, after the foiled Basco's attempt to get it.

The Legendary Hero, Don Dogoier
Aboard the Gokai Galleon, the crew was shocked to find Doc in a magazine, labeled as a hero who was said to have died defeating the an evil planet-eating dragon. Doc apologized for lying that he was a refugee from a Zangyack planet while admitting that he had no memory of doing such a thing. In hopes of regaining his memory, Doc dined at a fancy restaurant with Luka, Gai, and Ahim where the story of how he joined the Gokai Galleon crew was revealed. Soon after, on their way to find dessert, the pirates were attacked by Damaras as Captain Marvelous and Joe arrived, the latter recognizing their foe. Transforming to fight him, the Gokaigers found themselves outmatched as Damaras lived up to his reputation as the Zangyack Empire's greatest warrior. They attempt to fall back, but Basco and Sally blocked their only escape route. As the others were taken out by Basco and Sally, GokaiRed was defeated by Damarasu. Basco then incinerated the others as Doc was knocked aside with Damaras taking Captain Marvelous to have him executed, while Basco took his Mobilate and Ranger Key. Left alone, Doc was horrified that all his friends were lost.

On the Gokai Galleon, Doc was distraught over the loss of his friends and admitted to Navi that he made up the magazine article that portrayed him as a hero as a joke. As he remembered when Marvelous first gave him his Mobirate, a message from Damaras came over the monitor announcing Marvelous's execution and the later subjugation of Earth. Doc was ready to give up claiming he can't defeat Damaras although he wanted to, and Navi reminded him of when he first came aboard and learnt how to fight in his own way and how the team always covered for each other. With that, Doc was inspired and arrives on Earth just before Marvelous is executed. While Doc held off the Gormin, Navi arrived and freed Marvelous. After Marvelous was freed, Doc admitted he hasn't thought any further ahead when suddenly Joe, Luka, Ahim and Gai turn up and reveal they were saved from Basco's attack by Sally. Damaras realized he's been betrayed too late as he is literally stabbed in the back by Basco. After taunting Damaras that he should not have underestimated Doc, he left assuring the Gokaigers he only helped them so they can collect the last two greater powers. After changing, the Gokaigers defeat the Dogormin with an all-green Gokai Change, with Don becoming the original green, Midorenger. Damaras confronted them and they fought him. Don and Marvelous combined their final wave attacks. The team then assembled the Gokai Galleon Buster and after the red charge failed to take him down, a green charge finished the job. He was then enlarged by Insarn, and proved more than a match for Gokaioh and Goujyujin however Doc assured everyone they can win. Summoning MagiDragon, Pat Striker, GaoLion, Fuuraimaru and Machalcon, the Gokaigers form Kanzen GokaiOh and hit Damaras with the Gokai Kanzen Super Burst which finally destroyed him. Aboard the Gokai Galleon, the Gokaigers enjoy dinner as Doc apologized for his joke. However the others assured him he truly is a hero before asking for seconds, causing Don to say "You could at least treat me like a hero!"

Super Hero Taisen
When Marvelous takes control of Dai-Zangyack and leads them in battle against Kamen Riders, Don and Joe join with Daiki Kaito (Kamen Rider Diend), who is looking for Marvelous' treasure, and Hina Izumi, a friend of Eiji Hino (Kamen Rider OOO), in finding out. They eventually meet the crew of the time-travelling DenLiner.

Personality
He is a pacifist who causes trouble because he wants to avoid fighting. When frightened, Don will cower behind either Luka or Joe, but mostly Luka, often resulting in an elbow to the stomach.

Ranger Key
The Gokai Green Ranger Key (ゴーカイグリーンレンジャーキー) is Don's personal Ranger Key which allows him to transform into Gokai Green. Whereas the keys of the 34 Sentai were created out of the sacrifice of their powers in the Great Legend War, the origin of the Gokaiger Ranger Keys is unknown, though it can be assumed AkaRed had a role in their creation.

As with the other Gokaiger Ranger Keys, this key is commonly used in the Gokaigers' Ranger Key-compatible arsenal and mecha for different functions and attacks.

This Ranger Key was turned into a Ranger puppet once, by Basco. Along with the other Gokaigers bar an incapacitated Marvelous, Don confronted and defeated the puppet Gokai Green.

Bounty
His bounty is initially 100 but this is eventually raised to 1,000. This is then raised even further to 5,000. And yet further to 10,000. And again to 300,000, boosted due to his part in slaying Damaras, though still the lowest bounty among the Gokaigers, not counting Navi.

Portrayal
Don Dogoier is portrayed by Kazuki Shimizu (清水 一希). Prior to the series, Shimizu specifically said he wanted to be TimeGreen but not just because he liked Timeranger; his family was friends to the family of Masahiro Kuranuki, who portrayed Sion (the very first alien Sentai hero and another Green), and he wanted to do it in honor of him. Kazuki Shimizu also appeared in A Day of One Hero, a mockumentary centering around his role as Don.

As Gokai Green, his suit actor is Yasuhiro Takeuchi (竹内 康博), whose previous role was Gosei Red in Tensou Sentai Goseiger and later served as suit actor for Blue Buster in Tokumei Sentai Go-Busters.

Dub names
In the Korean dub of Gokaiger entitled Power Rangers Captain Force, which aired in South Korea, Don as with the rest of the first five Gokaigers keeps his name (likely because they are not from Earth and thus don't have normal Japanese names), while his Ranger designation is Captain Green.

Trivia

 * Don shares a few things in common with 4 out of 5 of the other Gokaigers in terms of counterparts:
 * He is one of three Gokaigers to not have a counterpart from every previous Sentai team, the other two being Ahim and Gai.
 * He is one of two Gokaigers to have all of their counterparts be the same gender as them, the other being Marvelous.
 * He is one of two Gokaigers to possess a ninja counterpart from a non-ninja Sentai team, the other being Luka. In Don's case, his is DynaBlack from Kagaku Sentai Dynaman.
 * He and Ahim share the same amount of different colored counterparts (4).
 * He and Gai share the same amount of Red Ranger counterparts (1).
 * Ironically, even though Don is a pacifist who serves as a comic relief, most of his counterparts (DenziGreen, GoggleBlack, DynaBlack, Green Two, Change Griffin, Green Flash, Black Mask, Black Turbo, Black Condor, MammothRanger, ShishiRanger, NinjaBlack, OhGreen, MegaBlack, GingaGreen, GoGreen, GaoBlack, KabutoRaiger, Bouken Black, GekiViolet, and Gosei Black) were the "tough and serious guys" of their groups.
 * His comedic counterparts include Midorenger, Clover King, Battle Kenya, Green Sai, FiveBlack, Green Racer, TimeGreen, AbareBlack, DekaGreen, MagiGreen, Go-On Green, and Shinken Green.
 * Taiyo Sentai Sun Vulcan is the only Sentai team where Don does not have a counterpart.
 * 2 of Don's counterparts (KabutoRaiger and GekiViolet) are neither Green nor Black Rangers. Coincidentally, both of these Rangers come from post-anniversary Sentai teams.
 * 3 Green Rangers (DragonRanger, Shurikenger, and Mele) and 6 Black Rangers (Black Bison, KingRanger, Black Knight, DekaMaster, Rio, and Go-On Black) are not Don's counterparts.
 * While MegaBlack is technically the leader of Denji Sentai Megaranger and Don's main Gokai Change for this team, Captain Marvelous continues to act as figurehead whenever the Gokaiger change into this team. Out of all the Gokaigers, Don has the least amount of leader counterparts, as Joe and Gai have none.
 * However, in Ep. 34: Dream Comes True, Don as MegaBlack appears in the center during the Megaranger change.
 * Unlike the other main Gokaigers, Don is not the first Green who is an alien: he was preceded by Timeranger's Sion.
 * Amazingly, Kazuki Shimizu (Don's actor) is family friends with Masahiro Kuranuki (the actor of Sion), with both coming from the same town.
 * Don is the only male Gokaiger who has transformed into more then one Extra Ranger/Bangai Hero.
 * He is the only member of the core 5 Gokaigers to have not lost a friend or family member.