"Eternal Night Vignette from the East") is a 2004 vertical bullet hell scrolling shoot 'em up video game developed by Team Shanghai Alice.

Imperishable Night introduces the 'partner' system, allowing the player a choice between four teams of two characters to switch between, each with their own shot type, in real-time.

The game begins at 11:00 PM, and with each stage, thirty minutes passes, or an hour if they fail to gather enough time points.

Some enemies use familiars that change their vulnerabilities depending on whether the player is playing as a human or a yōkai at the moment.

After multiple battles, including one with Reimu or Marisa (depending on who the player character is), who was also searching for the answer, the protagonist reaches Eientei, the mansion of the perpetrator.

Having completed the Five Impossible Requests, the team is given another challenge by Kaguya in the Extra Mode: defeat her rival, Fujiwara no Mokou.

Imperishable Night was created by Team Shanghai Alice, which consists of a single member, who goes by the pseudonym of ZUN.

ZUN had considered the idea for Embodiment of Scarlet Devil, but he felt that having playable characters that had not previously introduced would be unnatural.

[2] Writing for Gamasutra, Michael Molinari singled out an aspect of Imperishable Night's stage design for analysis: the stage two boss had a gimmick that limits the player's field of view and "bring[s] the most tension, excitement, exhilaration, etc., despite it simplifying the game and bringing me to the most primitive of mechanics (the process of movement)".

[3] Touhou Bōgetsushō (東方儚月抄) is an extension of the story in Imperishable Night, split into three parts, each carried by a different Ichijinsha magazine.

Cage in Lunatic Runagate is a novel being serialized in the quarterly Chara Mel; it centers on the viewpoints of the characters around the story.

However, as development of Mountain of Faith progressed, ZUN decided that he should base the story on something that Touhou Project fans were already familiar with.

[citation needed] He turned to Imperishable Night because he felt the game did not provide much room for character development despite having such a rich cast.