Sayaka Miki

Sayaka Miki
Japanese Name	美樹さやか (Miki Sayaka)
Seiyū	Eri Kitamura
Age	13-14 (estimated)
Weapon	Sword

This section may contain major spoilers!

Please refrain from reading if you are not yet familiar with all the latest media released.

Official Info

Madoka’s classmate and good friend. Energetic and lively, which is perhaps why her sword is the only melee weapon among the four.
Ms. Aoki’s Design Check!: Her personality is so boyish that I had to be careful not to make her look too boyish too. So I gave her hair a diagonal line in back, to straddle the line between short and medium length.
Magical girl outfit: Sayaka’s outfit is the closest to combat gear. Since her sword is a melee weapon, I paid attention to that while designing her clothes. (Aoki)
Her outfit features diagonal-cut skirt and shoulderless top for ease of movement. Add a cape, and she’s a picturesque swordswoman.
School uniform: Her figure is flat and plain, but her chest is bigger than Madoka’s. Her hairbow is a stitched design. Below, she wears simple navy-blue high socks.
Sayaka seems to have had an extremely black-and-white and idealistic vision of love, which seems to have contributed to her breakdown. She made a contract to heal the arm of the guy she has a crush on (Kamijou), but after learning the truth about the Magical Girl deal, she felt that she couldn't approach him, and this wasn't helped by Kamijou's obliviousness to her feelings and Hitomi's more assertive behavior that ended up with Hitomi becoming Kamijou's girlfriend, unaware of Sayaka's problem. That threw her in a self-destructive spiral, in which she refused help from others (specially Kyouko and Madoka) and seeked to either die or kill to dull the pain.
Sayaka turns into a witch named Oktavia von Seckendorff in Episode 8. While she has brought hope to others, the balance between hope and despair is then mitigated by an equal amount of despair appearing in Sayaka's soul. This despair eventually overcomes Sayaka, shatters her Soul Gem, and turns it into a Grief Seed.
Her witch form was killed by Kyouko in Episode 9; Madoka and Kyouko attempted to bring Sayaka back to her normal form, but according to Kyuubey that was impossible.

Fun Facts

The first character in her last name (美) means "beauty". The last character (樹) means "tree". Her name could also be written 幹 (tree trunk) or 神酒 (sake offered to the gods).
Saya（莢）　means husk in which seed of leguminous plant is wrapped.
Her last name can also be used as a first name.
Her first name is written in hiragana, which has no special meaning. However, "sayaka" could also be written 明か (obvious) or 清か (clear).
She describes herself as having been born "petit bourgeois," which is French for "petty bourgeois." This would mean that her family is at least from the middle class, but is by no means from the upper class (despite the fact that, if Japan has even less living space in the future than it does now, her family's apartment is far larger than a normal middle-class family could afford).
Although her character design depicts her with a two-edged sword she is seen using a katana with a saber-like guard in the anime. The manga uses the sword from her original design.
According to recent interview, "Sayaka had her personality based on a 'Urobuchi Gen character'"
When Sayaka transformed in the train in Episode 8, the fate of the two hosts was open to interpretation in the original scenario. Therefore, while Shinbo has recently confirmed that Sayaka did not kill the two gentlemen in the anime, they were in fact killed in the manga version.

Speculations and Observations

Many fans believed Sayaka is the witch in Madoka's dream at the beginning of Episode 1. However, this has been disproved by Sayaka's witch form hinted in Episode 8 and shown in full in Episode 9, which is entirely different in appearance from the witch Madoka saw.
While using her magic, circles of notes are sometimes seen around or near her. This is believed to be related to her wish to heal Kamijou.