Cirno's Perfect Math Class

Cirno's Perfect Math Class

Part of a series on Touhou Project (東方Project). [View Related Entries]

Updated Mar 28, 2012 at 12:45AM EDT by Hiroman.  

Added by Hiroman.

Like Know Your Meme on Facebook!

PROTIP: Press 'i' to view the image gallery, 'v' to view the video gallery, or 'r' to view a random entry.

This submission is currently being researched & evaluated!

You can help confirm this entry by contributing facts, media, and other evidence of notability and mutation.


Cirno’s Perfect Math Class (Japanese: チルノのパーフェクトさんすう教室 Chiruno no Pāfekuto Sansū Kyōshitsu) is a song remix arranged by ARM, member of the doujin group IOSYS.[1] The song is derived from a BGM (background music) of the popular vertical scrolling shooter game Touhou: The Embodiment of the Scarlet Devil.[2]

The video (MAD Movie) can be watched as a flash animation in its official site.[3]

The original movie was uploaded in Nico Nico Douga in 2008, garnering more than 4 million views.[4][5]

  • Cirno’s Perfect Math Class (High Definition):


The original song, “Beloved Tomboyish Daughter” (おてんば恋娘, Otenba Koimusume) is a BGM (background music) played during the game’s 2nd level boss fight against Cirno, an ice fairy. This song was composed by Team Shanghai Alice’s sole member, ZUN.[6]

The remix, “Cirno’s Perfect Math Class” was arranged by ARM, the lyrics was composed by Yoshimi Tano (夕野ヨシミ), and vocals by miko, all of whom are members of IOSYS. It was featured in the music album Touhou Anthology of Ice and Snow (東方氷雪歌集 Tōhō Hyōsetsu Kashū) by IOSYS, a doujin (indie) music circle, and released in 2008.


Full song with extended video:

Cirno (aka ⑨/ Nine-ball)

Cirno has been considered slow-minded, and often referred as “baka” (バカ, idiot, moron, fool) instead of her name. On the Phantasmagoria of Flower View manual, Cirno is labeled “9. Moron” in the explanation of the game layout . Hence, ⑨, or simply the number 9, has been associated with “baka” and Cirno.


The video has been used in several ways. For example, collective dances were performed using this song. Sometime in winter 2008-2009, Japanese users created a dance to the full version of Cirno’s Perfect Math Class. The earliest video posted on YouTube shows six people dancing in sync in the snow:

As the song became more popular, a larger number of people performed the dance, even reaching 300 participants.

Cirno’s Math Class in Beijing, China:

Covers have been made using classical instruments.

Piano cover by marasy8:

Violin cover by The Screamer:

Remixed with the Angry German Kid (aka Tapioca or Keyboard Crusher in Japan):

A “math training” flash game was also created, where the player must select the incorrect answer from a single digit sum within a time limit. However, if one of the options is nine, that answer should be selected instead regardless if the answer is correct or not.[7]

In 2010, a new version, “Cirno’s Perfect Health And Physical Education” ( チルノのパーフェクトほけんたいいく Chiruno no Paafekuto Hokentaiiku) has been included in the music album Touhou Love Strawberry Girl + by IOSYS, released in Comiket 78.[8]

Search Interest

External References

Recent Videos 61 total

Recent Images 18 total

Top Comments

+ Add a Comment

Comments 35 total


+ Add a Comment

Add a Comment

O HAI! You must login or signup first!