Sei Ashina was born Igarashi Aya, and assumed the stage name Sei Ashina. Prior to her acting career, Ashina was a model. She made her acting debut in the 2002 TBS Television series The Tail of Happiness (しあわせのシッポ）, modeling that year in magazines including Shogakukan's CanCam and Shueisha's Pinky, and was best known for starring as Hime in Kamen Rider Hibiki. She was also known for her role as The Girl, an unnamed concubine, in Silk (2007).
Kishu Hanshu Yoshimune
Cat Taxi
Neck Bowed in the Rain
As Ofumi
Kamogawa Horumo: Battle League in Kyoto
As Kyoko Sawara
BILIBILI MACRO LINK 2023
Damned Files 6
Killing for the Prosecution
As 運び屋の女
ST Keishichou Kagaku Tokusou-han
As Yuki Midori
Elevator Trap
Kamen Rider Hibiki: Asumu Transform! You can be an Oni, too!!
As Super Hime
The Tale of Genji: A Thousand Year Enigma
As Yugao
Nanase futatabi
Je t'aime: I Am a Beast
Cycle Soul Apartment
As Minami Miyata
Kamui
As Mikumo
Saru Lock: The Movie
As Ritsuko Mizuhara
Specialist
As Yuiko Matsubara
IMPOSSIBILITY DEFENSE
As Risa Yumehara
Hard Romanticker
As Natsuko
KING GAME
As Chekov
Koibone
As Sayoko
Pancakes
Specialist 3
As Yuiko Matsubara
Specialist 4
As Yuiko Matsubara
Kazura
As Ryoko Makida
Specialist 2
As Yuiko Matsubara
The Last Revenge
ST: Aka to Shiro no Sôsa File the Movie
As Midori Yuki
Silk
As The Girl
Brutus's Heart
As Hoshiko Nishina
Kaidan Horror Classics
Perfect World
As Aoi Nagasawa
Kamen Rider Hibiki The Movie: Hibiki & The Seven War Oni
As Hime
Love Police
AI Amok
As Maika Hayashibara
Rooftop Apartment
As 由香
World's End / Girl Friend
As Satomi
A Murder Is Announced
As Tsukimi Usako
Uta Monogatari: Cinema Fighters Project
As Kaori Kitada (segment "Our Birthday")
Stand Up!!
As Uehara Mio
Giragira
Saru Lock
As Ritsuko Mizuhara
Ano Ko ga Umareru...
Real Clothes
Dollhouse
As Mei
Keigo Higashino 3-week drama SP series
As 仁科星子
Yae's Sakura
As Yukiko Jinbo
Emergency Room 24 Hours
As 奈良さやか（なら さやか）〈29〉 演 - 芦名星
ねこタクシー
Bloody Monday
As Kaoru Minami
Je t'aime: I Am a Beast
As Yuka Murakami
Kamen Rider
As Hime
The Good Wife
As Misaki Kuriyama
AIBOU: Tokyo Detective Duo
As Fuko Kazama
Cleopatra na Onnatachi
The Future is in Our Hands!
As Nakanishi Sara
Kuroshoin no Rokubei
ST MPD Scientific Investigation Squad
Kurokouchi
As Madarame Yaeko
Soumatou Kabushikigaisha
As Kurose Yuka
Untouchable
As Misuzu Makise
The Specialist
As Yuiko Matsubara
The Knife and the Sword
As Kaede
Natsuko Kira
The New King
Daisy Luck
Angels with Broken Wings
It Was Fun Last Night
妖しき文豪怪談
The Ship of Theseus
As Noriko Sasaki
One Page Love
As Yaginuma Yoriko
スワンの馬鹿 こづかい３万円の恋
As 카즈키 아야나
The Tragedy of the “W” Prefectural police
Copyface
Futagashira
Hand of God