The official Twitter account for the Touken Ranbu: Hanamaru anime revealed on Saturday that a "new Hanamaru story" is in the works with a new project. The Twitter account did not specify the medium of the project, but stated it will take some time before the staff can reveal more information.
Touken Ranbu: Hanamaru is part of DMM's overall Touken Ranbu franchise, and follows the Touken Danshi characters in everyday situations in their more peaceful moments in the citadel.
The first season of the anime premiered in October 2016, and had 12 episodes. Crunchyroll streamed the season as it aired in Japan, and Funimation streamed an English broadcast dub. The Zoku Touken Ranbu: Hanamaru. sequel series premiered in January 2018, and also had 12 episodes. Crunchyroll and Funimation both streamed the series as it aired.
Saru Hashino launched a Touken Ranbu: Hanamaru manga on Shueisha's Shonen Jump+ website and app in December 2016, and ended the series in April 2019.
Source: Touken Ranbu: Hanamaru anime's Twitter account via Otakomu