Angelique Maren no Rokukishi is one of the collaboration projects between Ruby Party and Otomate, two well-known developers in the otome game genre. It was first announced at their first collaboration stage event, Japan Otome ♥ Festival.

Maren no Rokukishi is based on the light novel, Angelique Tenkuu no Requiem ~Kuroki Tsubasa no Moto ni~, a narrative which preludes the events of Angelique Tenkuu no Requiem. Like the novel, the game is set within Leviath's galaxy and takes place during the tail end of his rebellion against the nobility of his homeland. The game roughly retells the novel but includes its own changes to the narrative. The director and producer is Hironori Oono, and the scenario director is Midori Kusanada, the same author of Kuroki Tsubasa. Character designs and illustrations were done by Yuuhi Higashi.

The Limited Edition box includes a character digest book and a variety CD with an original drama and an image song for Leviath. Pre-ordering the title granted the drama CD, Sono Kuchiburu wa Dare no Mono? ("Who Claims Those Lips?"). Other pre-order bonuses were offered at various stores/online shopping sites.

The protagonist is an orphan who has no memories of her parents. She is raised by a family acquaintance and acts as the elder sister for their son, Renaud. One day, Renaud is missing and the villagers fear the ensuing wars too much to look for him. When the protagonist searches for him, she learns he has been recruited by Leviath and is one of his knights. The protagonist fears for his safety and decides to stay with the knights. As she does, she learns that she harnesses a mysterious power which helps Leviath's cause and learns about her lost past.