[1] The group was formed in 2008 by producer Maiko Fukushima, and released one indie single before undergoing some member changes and being signed to Lantis and Toy's Factory.

Since then, they have released several charting singles and albums, performed many concerts around the world, and appeared in several television shows and a 2013 film.

[citation needed] Taking this opportunity, Fukushima considered changing Dempagumi's name to "renew it to a new feeling", and I will consult with Saeki.

[14][15] According to Saeki, it is absolutely necessary to avoid unit names ending in "gumi" because they will be a follow-up to the aforementioned Ushiroyubi Sasaregumi.

After their first one-man performance at Harajuku Astro Hall,[27] Atobe graduated, and Moga Mogami and Ayane Fujisaki joined.

(武道館公演決定!, Budōkan Kōen Kettei) was projected on the screen, and it was a surprise announcement that the Nippon Budokan performance would be held.

[32] The members who had not been informed in advance cried, and Furukawa said, "I am really happy because I wanted to go to the Budokan during this year,"[32] and "a dream really comes true.

[citation needed] On October 19, their first show on terrestrial television, Denpa Jack -World Wide Akihabara- [ja] debuted on Fuji TV.

On October 25, they performed at "Anime Idol Asia" in Bangkok, Thailand, alongside Yumemiru Adolescence and the Kamen Rider Girls.

[41] On September 26 and 27, they held a live performance at the Lake Kawaguchi Stellar Theater [ja], claiming that it will be the final round of the World Tour (consecutive appearances to overseas Japanese cultural events) in June and July.

in January 2017 in three arenas: the World Memorial Hall; the Makuhari Messe; and for an extra performance on the 20th, the Nippon Budōkai.

[63][64] On August 6, Mogami announced on her blog that she left the group on the same date: My mind and body became out of balance, and it became very difficult to work in Dempagumi.inc.

[68] They appeared as a special guest at the reception party of Takashi Murakami's solo exhibition at the Garage Museum of Contemporary Art in Moscow, Russia on September 28 and presented her first live performance with a new five-member system.

[citation needed] At the Osaka Castle Hall on December 30, it was announced that Rin Kaname and Nagi Nemoto would join Dempagumi.inc.

[citation needed] Dempagumi.inc served as headliner several large festivals, including Idol Yokochō Natsumatsuri [ja] 2018.

They have also appeared in events across the country and abroad, and also visited three live houses in the "Tohoku Danpa Daisakusen" in early August.

In "Okinawa Special Edition" held on October 13 and 14, Nemu Yumemi stated that he would graduate on the second day of Budokan performance on January 7 of the following year and retire in March.

[citation needed] On April 9, 2020, the first sub-unit, NemoPero from Dempagumi.inc (ねもぺろ from でんぱ組.inc) was formed[73] by the newest members Nemoto Nagi and Rin Kaname with the release of their first single Shukishukishukipi♡gatomaranai ...!

[74] At the end of the second day, five new members, Kozue Aikawa, Rito Amasawa, Ria Kobato, Aozora Sorano, and Hina Takasaki, joined Dempagumi.inc, with the announcement of a new song.

[75] A new sub-unit, Chape No Izumi, was formed on May 5, 2021, with members Ayane Fujisaki, Kozue Aikawa, and Ria Kobato.

[80] In a blog post released on October 28, 2022, it was announced that Kozue Aikawa would graduate from Dempagumi.inc at December 31, 2022, citing health problems.

[81] In a blog post released on October 11, 2022, it was also announced that Aikawa also will be absent from future events due to health problems.

[82] In a blog post released on September 11, 2023, it was announced that Aozora Sorano would graduate from Dempagumi.inc at January 13, 2024, to focus on her activities in Arcana Project, which she had concurrently done along with Dempagumi.inc.