Undercover Agent Haruka: False Submission

"Oniyama, the head of a secret organization... is famous for being cautious. He never leaves a record of organizational charts, trading partners, etc. It's all in his mind, so he has no choice but to find out directly." "Oniyama is currently looking for a secretary for a company that is open to the hospital. He will get a job, then intervene in his behind-the-scenes work, become his direct subordinate and get in touch with information," "...I'll jump into the pockets of the enemy boss. It's reckless." "But we have no choice!" Female investigator Haruka sneaks into the enemy organization. He approached Oniyama, took over as a secretary and mistress, and extracted various secret information. Three months of infiltrating...the chance to get the most decisive information has arrived. But that night...