Gunshot and Diamond

Juusei to Diamond is a crisis negotiation visual novel adventure game on PSP. Players control negotiation expert Onizuka Youichi, a former New York police officer, who joins the Police Department's ZERO Squad. Gameplay revolves around hostage and criminal standoffs where players select dialogue options to influence negotiations, observe reactions, calm the suspect, or provoke them in timed sequences to resolve cases and uncover truths. Key characters include Onizuka Youichi, the psychological analyst Nakamura Keisuke, and various criminals in the cases. It stands out for its realistic adult-world setting, tense decision-making mechanics that simulate real negotiations, and emotional depth in character interactions and endings.