南西 祭段

Altar of The Underworld

Nansei17remake altar of the underworld cover
Artist LENK64
Released January 29, 2018
Tracks 17
Followed by Dark Mountain of Sins

Nansei Saidan ~ Altar of The Underworld (南西 祭段 〜 Altar of The Underworld lit. Festival Stage from the Southwest) is a remake of Broken 4th Dimension and a prequel to Dark Mountain of Sins.

It features a new cast of characters and playable characters, along with a new story and OST. It is the third Nansei Project to get a remake.

This project retcons the story of Broken 4th Dimension entirely and takes its place in the Nansei universe's timeline.


The story presents Kooya Senshi, who is looking for her master.

Similarities with Broken 4th Dimension

While AoTU takes B4D's place in the Nansei timeline (likely due to B4D's plot), it notably shares a similar cast of characters as it despite having a different story altogether:

  • Umbra could be seen as a parallel to Wyra Sonohoka, as both are smaller youkai with the ability to copy others (Wyra is a mimic and mimics lifeless objects, Umbra imitates spells)
  • Mai Uranaishi bares some similarities to Lunar Tsubasa appearance-wise in hair style and clothes
  • While You Nashi and Sasami Demomira are very different, both like to mess with humans (Sasami pulls pranks, You misleads others with her words)
  • Naomi Baisotei bares a resemblance to Amarella, both being nuns (and are also the same age; 28)
    • They both desire to make the world better and have different "fighting" styles; while Amarella prefers to use her wisdom and intelligence, Naomi instead uses her physical strength
  • Kage could be seen as similar to Ikuto Koketsuno, both being dark, intimidating monsters and also both being the Stage 5 mid boss and boss of their respective projects
  • Isabella Mihara could also be a parallel to Mirai Chasov, as both are Final bosses and extra mid bosses with green hair and are sitting on something (Mirai has a clock, Isabella has her altar)
    • They both also have similar, selfish goals (Mirai wishes to have a student take over her role as the Clockmaster of Kuusou no Sekai so that she can be free, while Isabella hypnotizes others and tempts them to step on her altars so that they become demonic beings and serve her in the Underworld)
  • Jaakuna Kiyomoto is parallel to Hora Clockwise, both being servants to the Final boss



  • It is the first Nansei Project to have only 2 kanji in its title as opposed to the standard 3 kanji.

External Links

Altar of The Underworld Playlist