Sailor Star Fighter Cast List
Sailor Star Fighter and the other Starlights appear late in the series and briefly. Even in the musicals, the characters only were introduced when the first stage was almost wrapping up and only lasted through the second stage (the official 'Second Stage' is through both Fumina Hara and Kanabe Miyuki's terms playing Sailor Moon). This could have been a good thing as the Starlight's characters were not really explored much in the anime or manga, which gives the actresses who played them less source material to draw from. Only two actresses played Seiya and Star Fighter, and they were:

Katayama Sayuri
Katayama Sayuri Out of Costume and as Sailor Star Fighter Profile:
First Name: Sayuri
Last Name: Katayama
Birthdate: June 3, 1979
Birthplace: Saga, Japan
Blood Type: A
Good With: Singing, Acting, Jazz Dance, Guitar
# of Myu Performances: 113

More Information:
Sayuri Katayama's Record Label Profile [Japanese]

She played Seiya like he was in the anime- a bit flashy, a bit arrogant, but a good guy. Sayuri did a good job with the duality of this role.

Musicals in:
Sailor Stars
Sailor Stars [Kaiteiban]
Eien Densetsu
Eien Densetsu Final Act [kaiteiban], Final First Stage

Akiyama Chinatsu Out of Costume and as Sailor Star Fighter Profile:
First Name: Chinatsu
Last Name: Akiyama
Nicknames: China-chan, Aki-chan Birthdate: July 13, 1982
Blood Type: B
Good With: ???
# of Myu Performances: 61 (as Star Fighter)


More Information:
Akiyama Chinatsu's Blog [Japanese]

She also played Mistress 9 in 2003's Mugen Gakuen Mistress Labyrinth - Kaiteiban.

Musicals in (as Sailor Star Fighter):
Starlights*Ryuusei Densetsu
Kakyuu-Ouhi Kourin