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Ami Koshimizu

Voice Actor

Ami Koshimizu has spent two decades voicing everything from fierce action heroines to soft-spoken video game leads, and in My Hero Academia she plays Sirius, the sharp-eared sidekick to the hero Selkie.

Agency: Office Restart
Role: Voice Actor
Nationality: Japanese
Years Active: 2003-present
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My Hero Academia Role

Koshimizu voices Sirius, a young hero whose Good Ear quirk lets her pick up faint sounds and high frequencies most people miss, which she uses to stay in constant contact with her partner, the pro hero Selkie. The pair work an ocean-patrol rescue beat, and Sirius's warm, encouraging manner comes through in scenes where she mentors students like Tsuyu Asui. It is a supporting role that Koshimizu plays with the same clarity she brings to bigger leads elsewhere in her career.

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Career and Notable Roles

Koshimizu made her name playing headstrong protagonists, among them Ryuko Matoi from Kill la Kill, Kallen Stadtfeld from Code Geass, and Holo from Spice and Wolf, and has voiced Sailor Jupiter in Sailor Moon Crystal and Yukiko Amagi in Persona 4. Her video game work includes Agnes Oblige in Bravely Default and the character Beidou in the Japanese dub of Genshin Impact, across a career that has run continuously since the early 2000s.

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Frequently Asked Questions

Who does Ami Koshimizu voice in My Hero Academia?

Ami Koshimizu voices Sirius, a young hero whose Good Ear Quirk lets her pick up faint sounds and high frequencies most people miss. Sirius uses the ability to stay in constant contact with her partner, the pro hero Selkie, on an ocean-patrol rescue beat.

What are Ami Koshimizu's most famous anime roles?

Ami Koshimizu made her name playing headstrong protagonists, including Ryuko Matoi in Kill la Kill, Kallen Stadtfeld in Code Geass, and Holo in Spice and Wolf. These roles established her as a lead voice actress well before her supporting turn as Sirius in My Hero Academia.

What other characters has Ami Koshimizu voiced?

Koshimizu has voiced Sailor Jupiter in Sailor Moon Crystal and Yukiko Amagi in Persona 4, adding to a career that spans multiple decades of Japanese anime. These roles sit alongside her work as Sirius in My Hero Academia.

What video games has Ami Koshimizu voiced characters in?

Koshimizu's video game work includes Agnes Oblige in Bravely Default and the character Beidou in the Japanese dub of Genshin Impact. That game work runs parallel to her anime career, which has continued since 2003.

Who is Ami Koshimizu?

Ami Koshimizu is a Japanese voice actress signed to the agency Office Restart, active in the industry since 2003. In My Hero Academia, she plays Sirius, a hero who mentors students like Tsuyu Asui during ocean-patrol missions.

Sources & Information

This content is original writing by Daddy Jim Headquarters based on the Dragon Ball anime series, manga, and official materials. Episode and chapter references are cited where applicable.

Character and scene imagery on this site is original artwork by Daddy Jim Headquarters, not screenshots or licensed imagery. Official cover art is used on three types of pages for editorial commentary:

  • Movie pages: theatrical posters and key visuals, credited to Toei Animation and Shueisha.
  • Game pages: official box art, credited to Bandai Namco, Atari, and other publishers.
  • Manga chapter pages: Jump Comics volume covers, credited to Shueisha and Akira Toriyama.

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