Seigi no Mikata ~Tadaima Kigae Chuu!~

The protagonist works as a social studies teacher, but he suffers from amnesia and only recalls the past three years starting from the moment he lay on an operating table at the headquarters of an evil organization. During that time, a compact bomb was implanted in his head to force his cooperation. At his school, a self-proclaimed female justice organization named 'Astrea' operates. It's only a matter of time before the two organizations collide.