I Want to Let Saejima-sensei go is a Manga/Manhwa/Manhua in (English/Raw) language, manga series, english chapters have been translated and you can read them here.
Thanks to an accident, Tanaka is able to see ghosts. One day, he visited the infirmary because he felt unwell, but the school nurse, Saejima-sensei tells him the shocking truth? A new spin in the horror comedy genre!