Seo Akira

A student at the Asagami Academy for Girls. Akiha's junior.
She appears in a side story included on the Tsukihime Plus Disc, “Alliance of Illusionary Eyes,” and also makes a cameo appearance in Kagetsu Tohya.
Her relationship with Akiha is a comparatively long one, and she has been Akiha's junior ever since she was a member of the middle school student council. She's in the somewhat comical position of idolizing Akiha, yet knows enough about her scary side to be afraid of her as well.
She secretly makes doujinshi in her spare time, though very few people at the academy are aware of it. Akiha is the only person that knows about how she sneaks into the bathroom in the middle of the night to work on it.
As far as boys are concerned, she's more attracted by their voices than their looks. When she heard Shiki's voice over the phone, it was a dead-center 150 kph fastball strike, or something to that effect. After that, she began to harbor a yearning for Shiki similar to adoration, but since she was scared of Akiha she never called him.
She has the power to see predictions of the future as images (future sight), and because of that ended up being dragged into a murder case.
According to Shiki, it would be great if she was his little sister. If Akiha ever found out he said that, it would end terribly for both Shiki and Akira.
Given that she attends the Asagami Academy for Girls, it should go without saying that she's a well-born girl. Her family runs a large liquor store in Aomori. As you'd expect from somebody growing up in that kind of environment, she can really hold her own when it comes to drinking.
By the way, in kanji “Akira” is written with the character for “crystal.” As in, a crystal ball that sees the future.

Tsukihime Dokuhon Plus Period: Tsukihime Dictionary Revised