Hal Skell

High school teacher Haruo Nemoto is seen as a dull, taciturn outcast at his school. Yet deep down, he cares for his students more than anyone else, a man of principle who just wants their youth to shine. But he has a secret: under certain conditions, he can make himself invisible. Armed with “that ecchi trope that all guys know about,” he will rise to the challenge every day to protect his students! (Source: Shogakukan, translated)