[Prepare yourself for here comes the longest bio of both of them ever! However the lines comes from female Aki. I'm too lazy to search male Aki's lines xP Also if I end up as playing female Aki, I will call her "Natasha"]

Aki Narukami (default name) is the protagonist of Misao. Aki is noted as being an ordinary high school student. Unlike most of their classmates, they alone off-campus. The player is given the choice to name the protagonist themselves; however, Aki is the default name.

In the Misao book published in July, the title reads "Case files of Narukami Aki". In Japanese, surnames are supposed to be said first as a courtesy act. Therefore, Aki's full, canon name is "Aki Narukami".

Aki was selected exclusively by Misao to find her and redeem her soul. This is because Aki had at least one interaction with her in the entirety of being classmates, none of which seemed to be negative. As no one really talked to Misao besides to condescend, Aki was the only one to talk to her in an inviting dialect. Misao first contacts Aki by appearing through dreams, and after sending the school into The Otherworld, Aki has visions/hallucinations of Misao's words; "HELP ME FIND ME" strewn about in a repeating pattern, written in blood.

Aki proceeds to scream as they lose composure under the pressure, and loses consciousness after presumably mental trauma, or being flung against an object, physical trauma, causing them to pass out. They wake up in the care of Onigawara in the Student council room. After a short briefing, Aki sets out to redeem Misao's soul.

As shown through a note on a bulletin board in a hallway, whichever gender of Aki isn't in use by the player claims that they're "always watching over" the current Aki in use. In the case of Male Aki, Female Aki will reach out beyond the spiritual realm and possess Male Aki, when need be.

Due to the aggressive and bullying nature of Yoshino, and the reaction of ecstasy acquired by examining Yoshino's mangled corpse, it is safe to assume that Aki was bullied by Yoshino enough to wish her gone/dead.

Throughout the game, Female Aki is shown as a kind and accepting individual, showing mercy to even Sohta when she learns of his murderous past. She is also quick to point out the wrongdoings of others, but will do her best to comfort anyone they see being upset. On the other hand, she does have a dark side, as she has no problem committing murder herself. This dark side is not apparent in her male counterpart, as he hesitates to commit the murders necessary to appease Misao.

In situations where Male Aki needed to murder Sohta/Tohma, he is unable to do it himself, due to extreme hesitation. If he decides that he should kill Tohma, he will leave the library, on the verge of tears, apologizing to Misao for being unable to do anything, and following, will hear struggling in the library. He later figures out that Tohma and Library got in a fight, and she killed him.

If Male Aki decides to kill Sohta, an unknown being (presumably Female Aki) will possess his body, forcing him to kill Sohta.

It is noteworthy, that unlike Male Aki, Female Aki never curses or swears; this is likely because since she's partially demon, she wouldn't be as emotionally affected at stressful events as someone without the soul of a demon.