"Oniyama, the boss of a secret organization... is famous for being cautious. He never keeps records of organizational charts or business partners. Everything is in his head, so the only way to find out is to find out directly." "Oniyama is currently looking for a secretary at a public company. I'll get a job there, then get involved in his behind-the-scenes work, become his direct subordinate, and get information out of him." "... I'll get into the arms of the enemy boss. That's reckless." "But I have no choice!" Female investigator Haruka infiltrates the enemy organization. She gets close to Oniyama, gets a position as his secretary and mistress, and extracts various secret information. After three months undercover, the chance to get hold of crucial information has arrived. However, that night...