Sayaka Mine

Sayaka Mine is the daughter of Raizo Mine and the main female character of the series, being Yaiba's friend and love interest. During the Kaguya Arc is revealed that she's also the descendant of the Dragon God Priestess.

Appearance
Sayaka is a young girl with long brown hair usually worn in a high ponytail adorned with a pink hairclip, noticeably taller than Yaiba. She's often considered beautiful or at least cute by other characters. She usually wears a typical school uniform with a blue long skirt, a white long sailor fuku with a red bolero tie as the fuku being blue with a single white lining and a matching blue folded sleeves and white sneakers and pink socks. Sometimes when she is at home, she often wears normal clothing as the series progresses.

In the anime, she was seen in two casual outfits. Her first casual outfit is a salmon pink sweater with a light yellow short sleeved button shirt as both sleeves are folded into cuffs, a sea green pleated skirt, and blue sneakers and light yellow socks and in Kaguya arc where she was mostly targeted by Kaguya for her youthful essence, she wears a purple short sleeve openly hoodie with zippers in each side, a yellow short sleeved loose shirt as the sleeves are revealed to be folded into cuffs to reveal her upper arms, an orange pleated skirt, and red and white sneakers and white socks. At home, she is mostly seen without her purple openly hoodie as she wears this when she goes outside or supporting Yaiba with his friends when he battles Kaguya.

When they swimming at the resort, Sayaka wears a hot pink one-piece suit with cross straps at the back and during the hot spring scene as both Yaiba, Kojiro and Musashi thought she was naked inside the spring, her one-piece suit is now pink and blue stripped with a single yellow lining. While wearing the outfit, Sayaka is seen with or without her pink hairclip.

Her sleepwear changes during their adventures, her pajamas can be seen in a different shades of pink with white polkadots and folded sleeves and the other being a light pink kimono dress. She always letting her hair down when she was sleeping.

When Kaguya absorbs her youthful essence and gaining her true primal form, her hair becomes white and both her face and skin became pale and wrinkled and the fringes of her hair is covering her eyes when she was depressed of losing her youth. Her eyes can be seen when Yaiba convinces her that she had changed which motivates her determination to rescue her friends.

In the series finale, she's grown even prettier and taller.

Personality
Sayaka sports an overall energetic personality and she has little patience for Yaiba and Musashi's perverted antics. In the anime, she was the only person to correct Yaiba by either punching his head or slapping to his face when he shows his arrogance or getting jealous.

While sometimes she appears to be bossy and demanding, in the end she's a nice person with a noble heart, often capable of taking serious decisions when required. She eventually develop a crush on Yaiba, though she only admit it at the end. In the anime, Sayaka is shown to be depressed after Kaguya absorbs her youthful essence and gaining her true primal form only for Yaiba to convince her that she had changed after rescuing her from drowning.

Abilities
Being a normal person, Sayaka has little fighting skills, since she practice kendo she can use a shinai in battle. During the Yamata no Orochi arc she gets to wield the Water Demon Longsword left by Rain. At the start of the episode in the anime, she carries a yellow umbrella where she hits Yaiba's head when they first met in the airport.

Weapons:

 * Water Demon Longsword ( 水魔の太刀 Suima no Tachi): The sword once belonging to Rain the Water Demon God, it appears as a very long katana with an oddly-shaped hilt similar to a western sword. The whole weapon is seemingly made of solified water, can stretch and generate water at will, and can phase through inorganic matter and cut flesh. Sayaka mainly uses it to shoot bullets of water, though Burner claimed that in her hands the sword is nothing more than a water gun.

Trivia

 * The "saya" from sayaka name stands for "scabbard", as noted by Musashi, she's the "scabbard" to Yaiba's "Blade".
 * Sayaka shared same voice actress with Kir/Hidemi Hondou from Detective Conan, which is also drawn by Gosho Aoyama.