|Height||155 cm (5'1")|
|Weight||43 kg (94 lbs)|
|Age||18 Years (Current Age)|
15 Years (Inside Heat Haze)
|Occupation||Founder of the Mekakushi Dan / Student|
|Status||Alive (Mekakucity Actors)|
Deceased / Inside of the Heat Haze (Songs, Novel)
Becomes Snake of Retaining Eyes (Manga)
|Manga||12. Yuukei Yesterday III|
|Anime||01. Jinzou Enemy|
|Novel||Kagerou Daze II -a headphone actor-|
|“||What do you think is the reason for my death?||”|
Ayano Tateyama (楯山文乃 Tateyama Ayano) was a classmate and best friend of Shintaro Kisaragi and the original founder of the Mekakushi Dan. She committed suicide by jumping off of the roof of her school.
- Ayano is a girl with long brown hair, with two red clips attached to her left fringe. Her eyes are colored in a dark brown, though they sometimes appear grey. In Toumei Answer, she is seen wearing a red scarf and a black school uniform with a white ribbon attached to it. Her stockings are black and her shoes are dark brown. As she grew up her school uniform changed into a lighter colored one with a bow attached at the chest area.
- At the end of Mekakucity Actors, she is seen wearing a white dress, trimmed with a thin red bow above her chest. 
- The daughter of a teacher, Kenjirou, and an archaeologist, Ayaka, Ayano was the founder and first leader of the Mekakushi Dan. Her member number at the time was "0".
- She was a cheerful girl who was Shintaro's classmate during middle and high school. Although always staying at Shintaro's side, she did not believe in her abilities to put him out of his apathy. It is presumed that she got rather low grades, as she was seen with only a 56 as a test score once and had to attend supplementary summer classes in her first year of high school. She also stated in the Mekakushi Radio #9, that she forgets things in class a few minutes after learning them; but it is shown that she can do well if she tries her hardest. Even though she called herself stupid, she was always smiling and seemed to be having fun. She is occasionally said to punish her brothers when they are misbehaving in a comedic way.
- Ayano cares deeply for her family and wants nothing more than for them to be happy, even if everyone couldn't be together. She treated her adopted siblings equally and always played with them when they were younger. Her sacrifice was the ultimate price she paid for her remaining family to be happy; even though she wanted to have her mother back, she refused to see anyone hurt or dead because of it.
- Favoring Eyes: (目をかける Me wo Kakeru) Her eye ability allows her to project thoughts and memories to others, which she refers to as "the power of caring".
- Toumei Answer
- Ayano no Koufuku Riron
- Lost Time Memory
- Additional Memory
- Ever Youth Roadshow
- Goodbye Summer Wars
- Her favorite character is Noriaki Kakyoin from JoJo's Bizarre Adventure.
- She tended to fold little paper cranes out of Shintaro's tests to cheer him up. Paper cranes stand for happiness and a long life, whether Ayano knew of this symbolism is unknown.
- She thinks the red jersey Shintaro wears suits him.
- It was confirmed by Jin that Ayano was Mekakushi Dan member No.0, as she was the original founder.
- In the Children Record Booklet it is stated that Ayano has black hair. However, she has never been shown with black, but instead always dark brown hair.
- She used to wear her hair clips in a cross shape when she was younger, then wore them parallel as she got older. The way her hair clips are placed may be to resemble her mother Ayaka.
- The hoodies she gave to Kano, Kido, and Seto when they were little were to help keep their eye powers from showing.
- Ayano is the first character to appear in the anime.
- "No, I'm no good for him. He needs someone that's even more selfish than him, someone energetic to pull him along... All I do is just follow behind him all the time. I can't do anything..." - Ayano about Shintaro
- "Ehehe. I’m stupid, you know. So it can't be helped." - (Children Record Booklet)
- "What do you think is the reason for my death?" - To Shintaro (18. Kagerou Daze I)
- "I hope everyone was introduced properly. Um, Mekakucity Actors is starting soon. We'll all do our best, so I'd be happy for your support. That was nerve-wracking...." - (Mekakucity Actors Commercial)
- "To be able to directly convey 'memories' and 'thoughts'... That's my ability! ...Favouring Eyes." - Ayano while explaining the Heat Haze to Hibiya (32. Shinigami Record II)
- "His grades in stuff like P.E. are terrible, though. And he loves stuff like music, though you wouldn't guess it. He likes shoujo manga, too. In spite of all the stuff he says, he has a loveable side." - To Takane about Shintaro