Rokutousei Supika is a manga by Onodera Akira, which ran in the Asuka magazine in 2000/2001. It’s composed of only one volume, which was released in December 2001. It’s only four chapters long, and is followed by a short story called Kaede. Onodera-sensei is also the mangaka of Hayabusa, currently runnung in Asuka (well at least it was recently, and there’s no tankoubon released yet).
Gotou Supika is a young woman who studies in a school that teaches… magic! More particularly, it teaches the art of fighting via magical devices which use astrology. There are three kinds of devices: the Star and the Moon (both are yin), and the Sun (yang). Supika uses the Star, precisely a Supika (yes, the same as her name), which is a kind of spirit with black wings and a black star under his chest. Supika are said to be the strongest device for women, who can at best attain level three out of a scale from 6 to 1. And when the story begins, Gotou Supika goes to see the head of the school to complain about her level being only 3 when she deserves to be on a highest level (well at least she’s convinced she deserves better). Basically the manga is about her fight to show her real strength in order to get the highest level of all, grade 1.
This fight takes form in her hatred for a level 1 student in third grade (actually the best student in the school and the son of the school head), called Amano Seiichi, the kind to look down on others. Amano is persuaded that women can’t be strong in magic, they’re nothing to him, so you understand why Gotou can’t stand him.
Astrology strength is determined both by the user’s ability, and by the strength of the device, the Sun seems to be the strongest of all, and is what Amano uses to fight. Also, a fighter using astrology needs an astronomer to use magic in the best way: with the help of a book, an astronomer can read future or give relevant details during a fight (as the enemy’s position or explications about the device they use).
Gotou Supika is extremely short tempered! She's easily pissed off and doesn't hesitate to shout or fight (she seems to really enjoy her powers this way). Only in first grade, she's stronger than the average women students and wants to be the equal as men. She doesn't like authority and is the kind to rebel against teachers. She hates Amano, and wants to win against him in a fight to prove her abilities.
Amano Seiichi is a third year student, but also the best and strongest student of the school, and the son of the principal. He's very scornful to women since he thinks they're weak. He's respected by all students, except Gotou of course. He himself can't stand Gotou since she's very self-confident, and actually said she could beat him up. He's just like Gotou, but in worse: proud, somewhat stubborn, convinced he's the strongest. However, he can learn from his mistakes, and finally admits Gotou is quite skilled.