Halskell summary:
High school teacher Haruo Nemoto is a boring and taciturn school hater.
However, his heart is a righteous man who cares about his students more than anyone else and wishes for their youth to shine.
He had a secret.
That is, to become an invisible person under certain conditions.
Using “that setting that boys in the world know somehow” as a weapon,
In order to protect the student's spring, he gets erect again today!