|This article is about a/an episode in Tokumei Sentai Go-Busters.|
Mission 20: 5 Man Concentration! Great Go-Buster (5体結集！グレートゴーバスター！ Gotai Kesshū! Gurēto Gōbasutā!) is the twentieth episode of Tokumei Sentai Go-Busters. It features the debut of Great Go-Buster, the combination of Go-BusterOh and Buster Hercules.
Finding Hiromu with a Christmas music box before he goes to sleep, Yoko learns from Usada that the music box is Hiromu's last present from his parents before the accident 13 years ago. The next day, the team arrives at the Makuta district after being alerted to a Vaglass Megazord's transportation within 5 minutes and 30 seconds. While there, the Go-Busters encounter the Metaloid Filmloid as he creates copies of the Go-Busters. The Go-Busters fight their copies until the Filmzord arrives and creates a barrier around its surroundings. After Filmloid teleports away once his copies are defeated, Masato and Jay arrive to reveal the barrier the Filmzord has created is a projection of subspace. He has been called in by Kuroki to reveal that the nature of subpace, Masato offers their only chance is to modify Go-Buster Oh to combine with the BC-04 Beetle and SJ-05 Stag Beetle so it can enter subspace and destroy the Megazord. Masato oversees the process, while warning Hiromu that it may cause him physical harm as he is the main pilot of the Megazord. The next day, with Masato and the Buster Machine crew still continuing their work, Yoko confronts Hiromu about the risks he is taking. He assures her that it would be okay and that that must save everyone. Alerted to Filmloid in the Iwatani district, the Go-Busters arrive and defeat the Buglers before Filmloid uses his projection ability to have them see their deepest desire in his new Sweet Dreams attack. Though Blue Buster and Yellow manage to see through it, Red Buster cannot as his deepest desire is to be reunited with his family. Losing against Filmloid, Blue Buster and Yellow Buster take a hit meant for Hiromu. But at the last second, despite Filmloid's gloating, Red Buster snaps out of the delusion in time to save his friends as he is forced to discard Filmloid's delusion to destroy the Metaloid with extreme prejudice. Once alerted that he has completed the modifications, the Go-Busters arrive as they, Masato, and Jay witness the formation of Great Go-Buster. Great Go-Buster then is deployed into the subspace projection, and they fight the Filmzord before destroying it. Upon seeing Messiah's apparent form as the subspace projection collapses and Enter falls back, Hiromu loses consciousness from the strain, but has a content look on his face.
- Hiromu Sakurada (桜田 ヒロム Sakurada Hiromu): Katsuhiro Suzuki (鈴木 勝大 Suzuki Katsuhiro)
- Hiromu Sakurada (child): Ryu Hashizume (橋爪 龍 Hashizume Ryū)
- Ryuji Iwasaki (岩崎 リュウジ Iwasaki Ryūji): Ryoma Baba (馬場 良馬 Baba Ryōma)
- Yoko Usami (宇佐見 ヨーコ Usami Yōko): Arisa Komiya (小宮 有紗 Komiya Arisa)
- Masato Jin (陣 マサト Jin Masato): Hiroya Matsumoto (松本 寛也 Matsumoto Hiroya)
- Cheeda Nick (チダ・ニック Chida Nikku, Voice): Keiji Fujiwara (藤原 啓治 Fujiwara Keiji)
- Gorisaki Banana (ゴリサキ・バナナ Banana Gorisaki, Voice): Tesshō Genda (玄田 哲章 Genda Tesshō)
- Usada Lettuce (ウサダ・レタス Usada Retasu, Voice): Tatsuhisa Suzuki (鈴木 達央 Suzuki Tatsuhisa)
- Beet J. Stag (ビート・J・スタッグ Bīto Jei Sutaggu, Voice): Yuuichi Nakamura (中村悠一 Nakamura Yūichi)
- Takeshi Kuroki (黒木 タケシ Kuroki Takeshi): Hideo Sakaki (榊 英雄 Sakaki Hideo)
- Miho Nakamura (仲村 ミホ Nakamura Miho): Fuuka Nishihira (西平 風香 Nishihira Fūka)
- Tooru Morishita (森下 トオル Morishita Tōru): Naoto Takahashi (高橋 直人 Takahashi Naoto)
- Rika Sakurada (桜田 リカ Sakurada Rika) (teenager): Rin Mizumoto (水本 凛 Mizumoto Rin)
- Enter (エンター Entā): Syo Jinnai (陳内 将 Jinnai Shō)
- Messiah (メサイア Mesaia, Voice): Seiji Sasaki (佐々木誠二 Sasaki Seiji)
- Filmloid (フィルムロイド Firumuroido, Voice): Kenichi Suzumura (鈴村 健一 Suzumura Ken'ichi)
- Yousuke Sakurada (桜田ヨウスケ Sakurada Yōsuke): So Yamanaka (山中 聡 Yamanaka Sō)
- Michiko Sakurada (桜田 ミチコ Sakurada Michiko): Michiko Hosokoshi (細越 みちこ Hosokoshi Michiko)
- As part of Super Hero Time, this episode aired alongside Kamen Rider Fourze episode 42, Archer's Reign.
- Viewership: 3.0%
- Great Go-Buster is assembled into its MegaZord form back at the base instead of in the field like almost all other Sentai Mecha.
- A catch-up talk of the first twenty episodes of Tokumei Sentai Go-Busters was aired as part of the Super Hero Max 2012 special event on TV Asahi. 
- At one point during the roll call, Blue Buster's visor appears to be orange and not blue.
- This is most likely eithor a lighting incident or editing mishap.
Tokumei Sentai Go-Busters Volume 5 features episodes 17-20: Mission 17: Its Name is Go-Buster Beet!, Mission 18: Cooperative Operations 3000 Meters In the Earth, Mission 19: My Combination! Buster Heracles and Mission 20: 5-Man Concentration! Great Go-Buster!. 
- Evox: Upgraded - Power Rangers counterpart in Beast Morphers. See comparison page. (Great Go-Buster's debut & combination footage)