|This article is about a/an episode in Hikari Sentai Maskman.|
The Great Destruction of the Underground Empire Castle! (地帝城大崩壊! Chitei Shiro Dai Hōkai!) is the fifty-first and final episode of Hikari Sentai Maskman. It is the conclusion of Maskman's four-episode endgame.
As Zeba finally unleashes eternal darkness upon the world, the Maskman must work with the twins of the Igam royal family and complete the restoration of light upon two realms.
to be added
- Ryousuke Kaizu as Takeru
- Koichi Kusaraki as Kenta
- Issei Hirota as Akira
- Yuki Nagata as Haruka
- Kanako Maeda as Momoko
- Hayato Tani as Commander Sanjuurou Sugata
to be added
- At the end of the episode, a preview for Choujuu Sentai Liveman airs for the first episode
- This is the last time the Maskman are together as a team, until the Great Legend War
- Ryousuke Kaizu (Takeru) will have multiple Sentai cameoes beyond this, including in Fiveman, Dairanger and Ohranger; his footage as Red Mask will likewise appear in Hyakujuu Sentai Gaoranger vs. Super Sentai
- Yuki Nagata (Haruka) appears in episode 6 of Fiveman
- Kanako Maeda (Momoko) will appear as Back Dimension Dimensian Soldier Kanna in two episodes of Jetman
- Issei Hirota (Akira) returns in a cameo in the fourty-ninth episode of Gokaiger
- Final Sentai Appearance of Kouichi Kusakari (Kenta)
- In the Philippine Dub, this is the last time being dubbed by ABS-CBN as the Sentai series has been replayed by another broadcasting company IBC-13 until 1998. Kim Atienza is mostly referenced by himself as the current voice actor of Takeru/Red Mask in later years when he reveals himself during his stint as a noontime show co-host of Its Showtime and being interviewed by fellow celebrity hosts in their morning show, Magandang Buhay.
- After Takeru allows Mio to restore the balance as an empress of the Underground Empire Castle and reunited with his team; Kazunori Inaba which is Ryousuke Kaizu's real name who portrays Takeru later marries a Filipino woman and Kapampangan native named Georgette Anne after his acting role in the Sentai series. They currently remained a couple who later owned a ramen shop and helping with other Sentai actors such as Michiko Makino from Choudenshi Bioman, Kenta Satou from Kousoku Sentai Turboranger, and Kei Shindachiya from Chikyuu Sentai Fiveman, hosted a tokusatsu charity event called Toku Spirits to show the fans who is the next Sentai actor will be mysteriously guested in the event throughout Southeast Asia except in the Philippines which his wife expresses disappointment and upset towards the researchers in Kapuso Mo! Jessica Soho due to the issue of cancelling the interview between them as the former apologizes for the issue they caused them.
- Despite the issue to be investigated by staffs from Kapuso Mo! Jessica Soho!, the charity event, Toku Spirits will be held at Metro Manila, Philippines in 2017 where they will reveal the fifth mysterious Sentai actor as their guest host.
- Ryousuke Kaizu is also the current representative for Hikari Sentai Maskman as the leader of Maskmen.
Hikari Sentai Maskman Volume 5 features episodes 41-51.