Nana to Kaoru -Kokosei no SM gokko
11/10/2022 Update
New Nana & Kaoru's spinoff, serialized on the newly released (28/11/18) digital magazine "Harem" (ハレム), aiming at adults.
The story takes place in the third year of high school, after the ending of the manga, but before Black Label (aka Arashi).