https://www.pixiv.net/en/users/1742503

a new teacher gets involved in the school's dark secret

full story is available in Pixiv description
https://www.pixiv.net/user/1742503/series/34419

while there's a "to be continued" at the end of Chapter 20 (no.689), it was 2 years ago (Aug 2018).. Given this artist's attention span, it's possible for this series to come back - but don't expect to much..

seems it is not the end yet, there are some CG after 689

Base +7