The Night Beyond The Tricornered Window

"The Night Beyond the Tricornered Window" should at least follow the main plot of the manga. The series is about the fateful meeting and team-up of Kosuke Mikado and Rihito Hiyakawa, who basically form a ghost detective investigation service. Kosuke is a shy bookstore clerk who can see spirits in the manga, but it's an ability he's not too thrilled to have — in fact, it scares him. Kosuke meets fearless exorcist Rihito by chance, and the two come together to start solving bizarre cases.

Fans can expect the series to pull from the manga's nine volumes of story to examine not only Kosuke and Rihito's cases together, but also their growing relationship. It has not been announced how many episodes yet the series will run, so there's no telling just how many volumes the anime television series will cover. 

The manga is also getting some additional content in August 2021, thanks to a three-chapter miniseries. This miniseries is meant to commemorate the upcoming anime (Anime News Network), so it's always possible that it could also somehow specifically tie in to the plot of the anime adaptation.