Naomi Tanizaki/Synopsis

Armed Detective Agency vs. Port Mafia Arc
Naomi is taken hostage by a bomber at their Agency office. With the help of Atsushi and Kunikida, the bomber was neutralized, but he managed to activate the bomb. Having no choice, Atsushi pushed Naomi away and covered the bomb with his body. When the bomb didn't activate, it was revealed all to be an act to test Atsushi. Naomi quickly hugged the bomber, who was her brother and overly excited how good he was while acting as the villain. She liked being tied and threatened and wanted them to continue that when they get home.

Later at Café Uzumaki, Atsushi couldn't believe Naomi and Junichirou were siblings, but she assured him. Atsushi ended up having to guess the members' previous jobs and he guessed Naomi and Junichirou were students and they confirmed. As they received news about a client, they all went back to the office. Hearing the client request, Kunikida assigned Atsushi and Junichirou to the job and Naomi decided to join to, so she can be with her brother. As the client led them to a dead-end alley, she revealed it was a trap and started gunning them down. Naomi stood in front of Junichirou and protected him with his body, who then in anger fought the woman, but was defeated by Akutagawa.

After the fight between Atsushi and Akutagawa at the cargo ship, Kyōka Izumi is brought to the Agency office, and Naomi is among the members playing with her. Atsushi is worried that, though Naomi and the rest enjoy Kyōka's company, someone law-abiding like Ranpo Edogawa might not easily forgive her murder crimes. However, he finds out right then that Ranpo enjoys playing with her the most, even offering her some treats.