Ecomoni (エコモニ。), was a Hello! Project subgroup formed in 2004. The purpose of the group was to promote environmental awareness. It was supposed to be a temporary unit, lasting from June 19, 2004 to June 20, 2004 but they had still made appearances together from time to time to promote various environmental festivals and events.
Their costumes represent the spirits of the forest and the sea.
- English translation:
- "I'm Rika Ishikawa. I'm Sayumi Michishige. Together we are Ecomoni."
- "Ishikawa Rika desu. Michishige Sayumi desu. Ecomoni desu."
- While saying "Together we are Ecomoni", they put their opposing hands together to form a V.
Ecomoni was created for the environmental festival "Acchi Chikyuu wo Samasunda!" (Cool Down the Hot Earth!), a two-day event which took place on the 19th and 20th of June. They were originally supposed to have disbanded after the festival during a ceremony to switch off the Tokyo Tower lights, however Koike Yuriko, Japan's Minister of the Environment, personally requested that they continue.
At the festival they sang their song "Help!! ~Ecomoni no Acchi Chikyuu wo Samasunda!~" which was written and composed by Tsunku. The song only appeared on a DVD available for purchase at the Festival and on the compilation album Petit Best 5. A new version sung with Morning Musume appeared on Petit Best 6.
In July and October of 2004 and in January of 2005, Ecomoni made a number of appearances on the TV show Oha Star.
At the end of 2004, they appeared and recorded the theme tune with co-star Matsuura Aya in the fourth Hamtaro film: Hamtaro in a Fairy Tale as Ecohamzu.
In 2005, Ecomoni and the whole Hello! Project became involved with the Japanese Ministry of the Environment's "Team Minus 6%" campaign to reduce Japan's greenhouse gas emissions to a level of 6% below the level of 1990 by 2012. They appeared with Minister Koike at the British Embassy in Japan on April 7 to promote the event.
On November 16, the girls released a joint photobook called Angels, though it was not a Ecomoni product.
On September 16 and 17th, Ecomoni, along with Morning Musume campaigned against global warming at Yokohama.
In 2007, it was said there would be a 2nd generation with Takahashi Ai and Kusumi Koharu, replacing Ishikawa Rika and Michishige Sayumi. They will be picking up where they left off, promoting environmental awareness. Though it seems no actions have been made.
Most critics claim that choosing Michishige Sayumi and Ishikawa Rika together in a duo, the supposedly vocally less talented Hello! Project members, is a bad idea when creating a music group, but defenders of the group counter by claiming that the group isn't only about the music, especially since Ecomoni hadn't released any music on their own.
- [2004-11-26] Tensai! LET'S GO Ayayamu (天才！LET'S GO あややム) (with Matsuura Aya, as Ayayamu with Ecohamzu)
- [2004.12.22] Petit Best 5 (プッチベスト5) (#16 Help!! ~Ecomoni no Acchi Chikyuu wo Samasunda!~)
- [2005.12.21] Petit Best 6 (プッチベスト6) ((#16 Help!! ~Ecomoni no Acchi Chikyuu wo Samasunda! 2005~)
- [2014.01.01] Hello! Project no Zenkyoku kara Atsumechaimashita! Vol. 2 (ハロー!プロジェクトの全曲から集めちゃいました! Vol.2 吉田豪編) (#15 Eco no Waltz)
- [2004-2005] Oha Suta
-  Hamtaro the movie: Hamtaro in a Fairy Tale
-  Acchi Chikyuu wo Samasunda (Festival)
-  "Team Minus 6%" campaign
-  Yokohama Campaign (Morning Musume)
-  Environmental Event (along with Morning Musume, v-u-den, Berryz Koubou and ℃-ute.)