[3] The group is a prominent act in the alternative idol and kawaii metal movements.

[4][5] Their name is taken from the Necronomicon, the famous fictional grimoire featured in the work of H. P. Lovecraft, combined with the Japanese words for magic (魔, ma) and necromancy (ネクロ魔, nekuro ma), and "idol".

[7][8] The group is managed by Ricky Wilson, an American expat living in Tokyo.

[9][10] They began with visuals inspired by a traditional Japanese "shrine maiden" look with "haunting" overtones, first seen in their earliest videos from 2014,[11] but their image later incorporated elements of the Cthulhu mythos as well as modern Japanese and Western horror.

[12] Necronomidol's style has been described as fusing J-pop with genres ranging from industrial music[13] to punk rock[14] to dark wave[5] to witch house[15] to shoegazing[16] to, most notably, heavy metal,[13][14][5][17] specifically the style of black metal.