Naoto Shirogane is a playable character in The Seventh Blade. A skilled private detective, Naoto is a refined, serious youth, with formal speech and body language.
A well-known detective, Naoto was dubbed the "Detective Prince" by the media. She is first mentioned when the department which Ryotaro Dojima works has no lead upon their investigations for the bizarre murder case, resulting in Dojima's superiors employing Naoto to assist them, an action which greatly disturbs Dojima. Furthermore, Naoto claims that the only rewards she wants for solving the case is the truth, and wants no assistance from other departments, further annoying Dojima.
Naoto first appears on-screen during the Investigation Team's investigation of Kanji Tatsumi as the potential next victim. Incidentally, Naoto was also able to deduce that Kanji would be the next victim, and tries to seek clues by speaking to him. During that time, Naoto expresses interest in the case, which Kanji mistakes as Naoto being interested in him. This results in Kanji becoming shocked and conflicted about his feelings towards Naoto, and more importantly, his sexuality.
Naoto later enrolls at Yasogami High School, immediately attracting the admiration of others. However, her serious nature often leads to her shunning and ignoring her admirers and classmates. Later, during one of the Investigation Team's meetings regarding the suspect in the case, Mitsuo Kubo, Naoto appears and chastises the Team's efforts, deeming their investigation as nothing more but a "game." She tells them that their game is about to end, and that Yasoinaba will soon return to its peaceful, rustic self. Annoyed by her words, Rise Kujikawa tells Naoto that she is the one who was treating the case like a game. Surprised by the idol, Naoto reluctantly accepts that what Rise said might be true, lamenting that detectives are just employed for the time being, and once the case has been solved, they are simply pushed aside.
After the arrest of Mitsuo Kubo, the first suspect in the case, Naoto remains suspicious and decides to become bait to lure the culprit. She is interviewed by a TV show and subsequently kidnapped and thrown into the Midnight Channel. Through the Team's efforts to gather clues, they found out that Naoto, despite her professional personality, is actually a workaholic who chooses to ignore the police department's advice and work alone. As such, she is often deemed a kid trying too hard by the officers.
The Investigation Team eventually manages to detect Naoto's location in the Midnight Channel, an industrial laboratory or military base filled with mechanical Shadows and falcon symbols, and sets out to rescue the detective. The Investigation Team eventually finds Naoto, along with her Shadow, who is busy preparing for a "body-altering operation." The other 'Naoto' taunts Naoto, saying that in reality Naoto is nothing more than just a child trying to play "superhero". Confused and surprised, Naoto denies the Shadow's claims. However, the Shadow then reveals a shocking secret: Naoto is actually female. It clarifies that the "body-altering operation" was to be a sex-change operation. Fueled by Naoto's rejection, her Shadow transforms and attacks the party.
Naoto's Shadow is a robotic doppelgänger equipped with large toy-like laser guns, rocket feet and a jet pack, representing Naoto's resentment towards being treated like a child and not taken seriously, as well as the pressure she feels from working in an occupation dominated by men. It can also be something of a split personality, as it can talk seriously one minute, and act helpless and innocent the next, similar to how the Wheel of Fortune may act unpredictably.
After defeating the Shadow, Naoto reveals that her parents were detectives as well, but were both killed in one of their investigations. She acknowledges her parents' passion for their job, and wishes to become a "hard-boiled" detective, inheriting the title of "Shirogane," but fears as long as she herself is a girl, she can never achieve her dreams.
She eventually realizes that what she wanted was not to become a man, but to be accepted as her true self