- Takane Enomoto: Enomoto Takane is Ene's past human self who underwent a 30 minute fixed-time "escape" from her home to nearby hills one day, after an eerie message concerning the "end of the Earth" was broadcast on TV. Takane was then given a count-down timer in the form of a mysterious voice in her headphones, who is believed to be Ene, conversing with her past self - that being Takane. At the end of the PV, Takane succeeds in reaching the hills before the time limit. At this time an unseen (by the viewers) third-party then tosses a bomb and destroys her town. As this occurs Takane hears Ene tell her that she is "Sorry."
- Shintaro Kisaragi: Ene's "master". She enjoys playing mischievous pranks on Shintaro, often messing with his system, re-naming his files, changing his passwords, and threatening to put his shameful private image stashes online, but she does care and worry for him and his thoughts over her. She regularly gets in, or starts, one-sided quarrels with him. In Route 01, Ene successfully forces Shintaro to leave his house in search of new computer components, thus resulting in his first encounter with the Mekakushi Dan. In Route XX, Shintaro gets fed up with Ene and kills her through unknown means. Before she transformed into Ene, Takane used to spend time with Shintaro (as well as Haruka and Ayano). It is shown that Shintaro is the only player who could beat her in the shooting game.
- Haruka Kokonose: Haruka was Takane's classmate in high school, and together they made up the only members of the Special Needs class due to their respective illnesses. Initially, Haruka's cheerful outlook on life greatly irritated the grouchy Takane, but as their time together progressed she began to develop feelings for him. Before she died, Takane's goal was to reach Haruka and tell him her true feelings. She was unsuccessful in this matter, which most likely influenced her time in the Heat Haze; running to get to a hill before time ran out, similarly as she was trying to reach Haruka when it occurred to her that he may not live much longer as his health deteriorates.
- Konoha: Two years after her death and transformation into Ene, Ene recognizes Konoha during the accident on the streets and was prepared to chase after him with Momo, when he was taken away with Hibiya in an ambulance. She remembers Konoha as a video game character Haruka created, when Konoha is in fact a body created by Haruka's desire to have an "ideal" body and the Snake of Awakening Eyes. Believing him to be dead, Ene cried and confessed to Konoha, but when he claimed to not remember her, she began to call him 'Imposter' instead.
- Kenjirou Tateyama: Takane and Haruka's former teacher, whom she would often insult and bribe with threats. Under the influence of the Snake of Clearing Eyes, it is implied that Kenjirou drugged and possibly even killed Takane, before taking her to his laboratory while she entered the Heat Haze and became Ene. Takane's body would stay at the laboratory for two years while Ene was separated from it.
- Azami: Azami once appeared before Takane and called her a "little girl". She said that there is no place for her anymore, but Takane strongly wanted to make a place for her current self to live on. Azami said that she must open her "eyes" to achieve that.
- Ayano Tateyama: She became friends with Ayano before she became Ene. Ayano told her that she should express her hidden feelings about Haruka to him. It is because of what Ayano said to Takane on the day she died that, since becoming Ene, she decided to infiltrate Shintaro's computer and wreck havoc on his life until he would eventually become more sociable.
- Momo Kisaragi: Momo tolerates Ene, because she doesn't live in her computer. Momo calls Ene "Ene-chan" and Ene calls her "little sister".
- Shuuya Kano: Takane met Kano at her school's cultural festival when he and Kido decided to participate in her game booth. As Ayano, Kano would listen to her ranting and had spent lunches with her. He assisted her in returning her to her real body in the fifth novel. Takane teases Kano for pretending to be Ayano and Kano tells that "she is like me in a twisted way" but the two become friends due to their common friendship with Ayano. In the anime, Kano transforms into Haruka and scolds her for what she is doing to Shintaro.
- Tsubomi Kido: Kido went with Kano, Shintaro and Ayano to Takane's cultural festival. Both Kido and Kano decided to play in Takane's booth. Back then, Kido couldn't control her power yet, so Takane didn't really notice her until after introducing the game. This lead to a frightened reaction from Takane, much to Kido's embarrassment. Later, when Kido 'cheated', she attempted to apologize but instead ran out of the room, only surprising Takane further. As Ene, she and Kido seem to get along, although the two do not converse often. Ene referred to Kido as 'Ghost Girl' when she remembered the incident at her booth, and Kido had once called Ene simple-minded when Ene instantly assumed a debt meant money.
- Kousuke Seto: Seto mistook Ene for being Shintaro's girlfriend from an online dating site. In the anime, Ene commented that he looked like he would be fun to tease.