|This article is about a/an episode in Ressha Sentai ToQger.|
Who Is He? He Is Whom? (誰があいつで あいつが誰で Dare ga Aitsu de, Aitsu ga Dare de) is the fourtieth episode of Ressha Sentai ToQger.
After transforming into ToQ 6gou, Akira fights the ToQgers when they refuse to leave without him. Though the ToQgers try to reason with him, Zaram assumes his true form as General Schwarz comes to him to carry out their plan. Zaram, after reminding Tokatti of their promise, accompanies Schwarz on his darkness reserve-powered Kurainer to raid Castle Terminal. With the Ressha giving chase, the ToQgers talk about Akira's words while Right intends to get their friend back. At Castle Terminal, Barone Nero and Madame Noir are confounded to find Miss Glitta having took over Emperor Z's body. Certain that it is the opportunity she has been waiting for, Noir knocks out Barone and attempts to free her daughter. But Glitta tells her mother she cannot leave Emperor Z's body before he regains his body and blasts Noir out of the castle. By then, Schwarz's Kurainer arrives as he and Zaram fight their way to throne room. It is then that Schwarz reveals he recruited Zaram to have him kill Emperor Z, weakened by the Darkness Decline, as ToQ 6gou. But Emperor Z uses much of his remaining power to defeat ToQ 6gou and abduct him on the Imperial Kurainer. Just as the ToQgers are about to enter the Shadow Line on the Drill Ressha, they see ToQ 6gou falling from the Imperial Kurainer with Schwarz's Kurainer in pursuit. But once they bring ToQ 6gou to the Ressha as Schwarz enters the Imperial Kurainer, the ToQgers learn that Emperor Z stole the AppliChanger from Zaram to seek refuge in the Ressha. But as the ToQgers discuss the turn of events, they see Miss Glitta manifesting as she requests them to stop Schwarz from saving her as she feels her separation from Emperor Z would only result in a catastrophe for everyone. Meanwhile, returning to find Castle Terminal having tremors, Marchioness Mork learns about the situation as she tells Nero that they must find Emperor Z. The ToQgers find Schwarz and Zaram, but are unable to give the former Glitta's message as they and the rouge Shadow Line members fight Nero and the Close as Hyper ToQ 1gou battle Marchioness Mork's Kurainer in Hyper Reshha Tei-Oh. Schwarz and Zaram eventually escape in the chaos, finding a wounded Noir as she pleas their help with Glitta. But as Marchioness Mork's Kurainer Robo is defeated, the unsettled Castle Terminal manifest with the ToQgers realizing it has been situated where their hometown Subarugahama used to be upon recognizing the tree where they used to play as kids next to the fortress.
- Right (ライト Raito): Jun Shison (志尊 淳 Shison Jun)
- Tokatti (トカッチ Tokatchi): Jin Hiramaki (平牧 仁 Hiramaki Jin)
- Mio (ミオ): Riria (梨里杏)
- Hikari (ヒカリ): Ryusei Yokohama (横浜 流星 Yamazaki Hikaru)
- Kagura (カグラ): Ai Moritaka (森高 愛 Moritaka Ai)
- Akira Nijino (虹野明): Shin Nagahama (長濱 慎 Nagahama Shin)
- Conductor (車掌 Shashō): Tsutomu Sekine (関根 勤 Sekine Tsutomu)
- Ticket (チケット Chiketto, Voice), ToQger Equipment Voice: Kappei Yamaguchi (山口 勝平 Yamaguchi Kappei)
- Wagon (ワゴン Voice): Yui Horie (堀江 由衣 Horie Yui)
- Emperor of Darkness (闇の皇帝 Yami no Kōtei, Voice): Kengo Ohkuchi (大口 兼悟 Ōkuchi Kengo)
- General Schwarz (シュバルツ将軍 Shubarutsu Shōgun, Voice): Haruhiko Jō (壤 晴彦 Jō Haruhiko)
- Baron Nero (ネロ男爵 Nero Danshaku, Voice): Jun Fukuyama (福山 潤 Fukuyama Jun)
- Madame Noir (ノア夫人 Noa Fujin, Voice): Aya Hisakawa (久川 綾 Hisakawa Aya)
- Miss Gritta (グリッタ嬢 Guritta Jō, Voice): Noriko Hidaka (日高 のり子 Hidaka Noriko)
- Marchioness Morc (モルク侯爵 Moruku Kōshaku, Voice): Reiko Suzuki (鈴木 れい子 Suzuki Reiko)
- Transfer Changes for Who Is He? He Is Whom?:
- to be added
- In the second battle against kuros,they decide to re-using the footage from the previous episodes.
- Tripping Scene: ToQ 4gou
- Everyone's Train Corner:
- As part of Super Hero Time, this episode aired alongside Kamen Rider Drive episode 10, What Is in the Belt's Past?.
- When Z reveals himself, Wagon notes that even Ticket can transform into ToQ 6gou. Ticket was the first one to transform to ToQ 6gou before Akira joined the ToQgers in "Station 17", he transformed one more time to face his archnemesis, Kaniros, in Ressha Sentai ToQger DVD special: Farewell, Ticket! The Wasteland Super ToQ Battle!, where he is refered to as 'Ticket 6gou'.
- After 16 episodes of absence, Noriko Hidaka returns to the series as the voice of Miss Gritta.
- Kengo Ohkuchi's (Emperor of Darkness Z) 33rd birthday, falling on November 9th 2014, was celebrated during filming of this episode. 
- TV Asahi's official preview for ｢誰があいつで あいつが誰で」
- Toei TV's official episode guide for ｢誰があいつで あいつが誰で」