|This article is about a/an episode in Kamen Rider W.|
|The Nightmarish H/The Melancholy of the Sleeping Princess|
|Kamen Rider W, Episode 29|
|Air date April 4, 2010|
|Written by Keiichi Hasegawa|
|Directed by Ryuta Tasaki|
The D Was Watching/Twin Maximum Suicide
The Nightmarish H/Who Is the Prince?
Shotaro accepted a request from a girl fearing a Dopant who attacks it's victims in their dreams which it can control.
After Akiko tells Shotaro of how she stayed up all night watching a jidaigeki DVD box set, a sleep deprived young woman comes in claiming she is unable to sleep because of a monster that has invaded her dreams like six other college students. Akiko deduces that it must be a Dopant, a fact that Philip goes to investigate out of interest.
After introducing herself as Himeka Yukimura and claiming Shotaro to be her destined "prince", she brings him and Akiko to Futo University where she is part of a lucid dream sleep study led by absent-minded Professor Akagi and his aid Hajime Fukushima. Ryu and Makura have also arrived to investigate the six comatose students who were helping in Akagi's project.
In order to capture the Dopant, both Ryu and Shotaro agree to use the same brainwave devices that the professor uses in his study, prompting Himeka to claim Ryu is her prince as well. That night, both Shotaro and Ryu attempt to confront the Dopant. As Shotaro attempts to watch Akiko's DVDs to bore him to sleep, only to have the opposite effect, Ryu has a bad dream about his sister Haruko marrying Jinno before the Nightmare Dopant appears to attack him. The Dopant uses his reality-altering powers to overpower Kamen Rider Accel before trapping him in a massive dreamcatcher.
By morning, Shotaro learns of Ryu's fate as Philip uses the Gaia Library with no success in determining the Dopant's identity. Returning to Futo University, Shotaro comes across Himeka who gives him a warning she received from the Dopant to stay away, but he refuses to accept the Dopant's threat. By then, Philip (followed by a strange bird) arrives with a plan to combat the Dopant by entering Shotaro's dream through their transformation as Kamen Rider Double.
After the two transform and Shotaro falls asleep with the brainwave device on, they find themselves in a jidaigeki-influenced Futo. They shortly come across the Nightmare Dopant, who wonders why Himeka is also in Shotaro's dream as he kidnaps her.
After transforming into Double in the dream as well, they chase after the Dopant who eventually reveals that he is capturing other men in their dreams so he alone can be Himeka's "destined prince". After escaping Double, the Nightmare Dopant is stopped by Philip, who is immune to the Dopant's power, asking the monster if he is Akagi. But the Dopant reveals that he has already trapped Akagi in a dream as well. Before he can determine the identity, Philip is forced into the real world by the Weather Dopant attacking Double in revenge for the Invisible Memory incident.
As Shotaro is forced to fight the Nightmare Dopant on his own, the Fang Memory attempts to protect Philip, but it is blown away and Philip is struck by a bolt of lightning, leaving him seemingly dead in Akiko's arms.
- Shotaro Hidari (左 翔太郎 Hidari Shōtarō?): Renn Kiriyama (桐山 漣 Kiriyama Ren?)
- Philip (フィリップ Firippu?): Masaki Suda (菅田 将暉 Suda Masaki?)
- Akiko Narumi (鳴海 亜樹子 Narumi Akiko?): Hikaru Yamamoto (山本 ひかる Yamamoto Hikaru?)
- Ryu Terui (照井 竜 Terui Ryū?): Minehiro Kinomoto (木ノ本 嶺浩 Kinomoto Minehiro?)
- Mikio Jinno (刃野 幹夫 Jinno Mikio?): Takeshi Nadagi (なだぎ 武 Nadagi Takeshi?)
- Shun Makura (真倉 俊 Makura Shun?): Shingo Nakagawa (中川 真吾 Nakagawa Shingo?)
- Santa-chan (サンタちゃん Santachan?): Zennosuke Fukkin (腹筋 善之介 Fukkin Zennosuke?)
- Ryubee Sonozaki (園咲 琉兵衛 Sonozaki Ryūbee?): Minori Terada (寺田 農 Terada Minori?)
- Saeko Sonozaki (園咲 冴子 Sonozaki Saeko?): Ami Namai (生井 亜実 Namai Ami?)
- Wakana Sonozaki (園咲 若菜 Sonozaki Wakana?): Rin Asuka (飛鳥 凛 Asuka Rin?)
- Shinkuro Isaka (井坂 深紅郎 Isaka Shinkurō?): Tomoyuki Dan (檀 臣幸 Dan Tomoyuki?)
- Narration, Gaia Memory Voice (ナレーション、ガイアメモリ音声 Narēshon, Gaia Memori Onsei?): Fumihiko Tachiki (立木 文彦 Tachiki Fumihiko?)
- Himeka Yukimura (雪村 姫香 Yukimura Himeka?): Natsuko Asō (麻生 夏子 Asō Natsuko?)
- Hajime Fukushima (福島 元 Fukushima Hajime?): Yasushi Kato ( 加藤 康 Kato Yasushi?)
- Professor Akagi (赤城 教授 Akagi Kyoujyu?): Nishi Fuyuhiko (西 冬彦 Fuyuhiko Nishi?)
- Haruko Terui (照井 春子 Terui Haruko?): Mika Kasahara (笠原 美香 Kasahara Mika?)
- Kyūzō of the Turret (櫓の久蔵 Yagura no Kyūzō?): Seizō Fukumoto (福本 清三 Fukumoto Seizō?)
- Heiji Hidari (左 平次 Hidari Heiji?): Kunio Nishimura (西村 匡生 Nishimura Kunio?)
- The H stands for Himeka and Horror.
- This episode aired on the same day as a rerun of the twenty-sixth episode of Kamen Rider Decade, as part of TV Asahi's re-broadcast of the series from beginning to end at the 6:30 am timeslot.