"Eastern Lands of the Scarlet Devil") is a 2002 bullet hell scrolling shoot 'em up video game developed by Team Shanghai Alice.

The story follows either the miko Reimu Hakurei or the magician Marisa Kirisame, as they fight through the world of Gensokyo to find the cause of a vampiric mist, covering the sky scarlet red in the midst of summer.

After a denial, ZUN then instead decided to develop a full game to submit at Comiket 62, reviving the Touhou Project series.

Due to the handmade nature of indie dōjinshi works, initial sales of the game were low, being sold for one day at a single Comiket booth.

Embodiment of Scarlet Devil is the only Windows game that does not show the player's hitbox while focusing – this is remedied in Perfect Cherry Blossom.

[c][1] The Touhou Project is set in Gensokyo,[d] a land sealed from the outside human world and primarily inhabited by anthropomorphic yōkai.

Marisa Kirisame, the other main playable character of the series, is a smug human who has become a magician through sheer hard work and generally prioritizes self-interest and her own kleptomania over the interests of others.

[8] Travelling in that direction, she encounters the yōkai Rumia,[9] and later the ice fairy Cirno,[10] determining neither are related to the mist – instead, the Scarlet Devil Mansion (紅魔館), which seems to have appeared from out of nowhere, is discovered to be the cause.

They leave, and Remilia realises that Patchouli has cast a storm over the mansion to prevent her younger sister Flandre Scarlet from escaping.

[21] After the release of the previous Touhou Project game, Mystic Square in 1998, ZUN, creator and developer of the series, graduated from university.

Mystic Square was intended to be the final Touhou Project installment as ZUN "sealing" his dōjin activities – he had originally planned to stop with Lotus Land Story.

ZUN left Amusement Makers in 2001, but continued to work at Taito until 2007, meaning each Touhou Project game until Mountain of Faith was developed concurrently with ZUN's work at Taito, which include Magic Pengel: The Quest for Color, Bujingai, Graffiti Kingdom and Exit, as well as some other games that were ultimately cancelled.

[25] The Embodiment of Scarlet Devil brings things back to the starting point, by curbing the game systems that change the difficulty in obscure ways while at the same time pursuing the natural fun of dodging bullets.

As ZUN was more familiar with APIs and DirectX and was relatively unfamiliar with the application level, a lot of time was put into creating libraries and tools for the game.

[30] This also allowed the game's plot to be contained within its own narrative – Embodiment of Scarlet Devil does not mention or feature any PC-98 era characters bar Reimu and Marisa.

Now regarding his past works as juvenilia,[31] the jump from PC-98 to Windows represented a "clean slate" for both ZUN and the series: Embodiment of Scarlet Devil essentially serves as a soft reboot.

[32] ZUN has since remarked how the general theme and direction of the Touhou Project only started to come together during the development of Embodiment of Scarlet Devil.

[33] ZUN's general goal for Embodiment of Scarlet Devil was to avoid over-complication, and to let the player have fun simply dodging bullets.

[25] The Spell Card system was created by ZUN in 1999 while working on the Seihou Project, and was intended to be a means to identify bullet patterns with names as well as adding depth to his characters.

[36][37] A portrait of an unused character named Rin Satsuki was used to advertise Embodiment of Scarlet Devil at Comiket 62 – she was ultimately cut from the game due to time constraints.

However, ZUN decided to arrange and re-record the soundtrack in WAV format using a Roland Edirol SD-90 he had recently purchased, just before the game was released.

ZUN does not plan to give any Touhou Project game an official English translation, stating that he has more faith in his fans to handle localisation than a third-party company.

In annual polls conducted by the Japanese Touhou Wiki, Embodiment of Scarlet Devil has been voted the most popular game each year since 2016.

spread virally online under the "Death Waltz" name, and the original piece is largely unknown by most, bearing no resemblance to "U.N. Owen Was Her?".

and Remilia's boss theme "Septette for the Dead Princess" have alternated between first and second place in music popularity rankings of the Touhou Project since 2014.

[62] Toby Fox, the creator of Undertale and Deltarune, has cited the Touhou Project as a major influence both musically and gameplay-wise, as he downloaded Embodiment of Scarlet Devil and Perfect Cherry Blossom during middle school.

Fantasy Kaleidoscope ~ The Memories of Phantasm (幻想万華鏡) by the circle Manpuku Jinja adapted the plot of Embodiment of Scarlet Devil to anime form[65] while Musou Kakyou: A Summer Day's Dream (東方二次創作同人アニメ　夢想夏郷) uses the setting and characters of Embodiment of Scarlet Devil in an original plot.

Summer Day's Dream is notable for starring high-ranking professional seiyuu, such as Rie Tanaka, Miyuki Sawashiro, Aoi Yuuki, and Aki Toyosaki.