Aiming has announced the official launch date for the upcoming mobile game, The Eminence in Shadow (陰の実力者になりたくて!マスターオブガーデン). The game will be available in Japan on the 29th of November on PC, Android and iOS. The pre-registration event is now underway.
Personally I have not heard about this light novel, seen the manga or watched the anime series. However, with the manga and anime adaptation and now a mobile game, I guess the series is quite popular in Japan?
Story aside, the game seems to be a hero-collection RPG with automated combat. You can collect the many waifus that are available in the original series.
The pre-registration campaign is now underway. Players can visit the official website to find out more details on the pre-registration rewards!