An idol unit consisted of 3 newcomer idols.
Having full knowledge of the beauty of woman, Seven Deadly Sins - Devil of Lust, Luxuria from Black World and the Cthulhu Nyarlathotep conducted scouts and interviews, and gathered amateur yet talented members.
Its investor is Atlach-Nacha, while its catalyst is Soma Kembuchi.
1. As usual, Luxuria followed her beloved Soma-kyun to the Tombcastle.
2. Soma-kyun was somehow fighting with the troublesome Seven Deadly Sins - Devil of Sloth, Acedia.
3. Then, Seven Deadly Sins - Devil of Envy, Invidia arrived. Angry with Acedia who is having personal dispute with the Tombcastle.
4. Luxuria invited the still-agitated Invidia and Acedia to a bar in the outskirt, and they hit off with Nyarlathotep in there.
"iDA" is a project created from the discussion of 3 Devils and 1 Cthulhu about "what is business management" over a drink. Even after Ira and Acedia has left, the discussion between Luxuria and Nyarlathotep continued over the night. Afterwards, Nyarlathotep assumed the position of manager.
While the circumstance behind its creation could be called as an accident, Luxuria decided that the ultimate goal is to create alluring songmaiden that fits the face hidden behind her smile. She later commented that she was inspired by "the twin(like) unit of Sera Kurashiki and Kasuga Kurosaki who soars over battlefield" that she saw when she visited Tombcastle.
Its main characteristic is all of its 3 elected members has their own special feelings for "song". Please look forward to their activities from now on.