"Gathering Dreams in the East"), commonly abbreviated as IaMP in English speaking circles, is a versus fighting game collaboratively developed by Twilight Frontier and Team Shanghai Alice released in 2004.

Because of Touhou's origins as a bullet hell game, Immaterial and Missing Power's special moves have a focus on large amounts of projectiles.

[1] Spell Cards, a central aspect of Touhou since Embodiment of Scarlet Devil, appear in Immaterial and Missing Power as special moves that have to be announced before they can be used.

[2] During Gensokyo's summer, there occurred an incident called the Night Parade of Ten Thousand Demons Every Four Days (三日置きの百鬼夜行).

Unabara Iruka (海原海豚) of the Twilight Frontier team had wanted to make a fighting game with aerial battles similar to Cyberbots: Full Metal Madness (1995) and Astra Superstars (1998), but felt that creating a whole set of characters and the setting just for the game would be overwhelming.

[12] Unlike the main Touhou games, which were written developed entirely by ZUN, the dialogue, character sprites, and ending artwork in Immaterial and Missing Power are drawn by alphes, an artist at Twilight Frontier.

[13] On April 2 2004, Twilight Frontier announced the production of Immaterial and Missing Power, with Team Shanghai Alice.