Mrs. Kasahara's most usual roles are soft-spoken young girls, usually of The Ojou or Naïve Everygirl type. She's also an Idol Singer (Sang "Ending Theme ~ Shadow Hearts" from Shadow Hearts) and a musical actress (she plays Retsu Unohana in the Bleach musical).
Notable roles by Hiroko Kasahara
- Fuu Hououji in Magic Knight Rayearth and Super Robot Wars T
- Naomi Armitage in Armitage III (Playing Against Type)
- Sayo Mutou / Magdaria in Rurouni Kenshin
- Ami Kurimoto in DNA².
- Sakura Tomoe in Weiß Kreuz
- Princess Azalyn in Irresponsible Captain Tylor
- Ishtar in Macross II
- Retsu Unohana (live-action) in the Bleach musicals.
- Princess Rose in Yu-Gi-Oh! GX
- Oniyuri Kageyama in Hyakko
- Nanako Misonou in Dear Brother.
- Yukina Kurimoto in Seraphim Call
- Akanegasaki Sora in Ever17
- Hinako Shiratori from Ultimate Teacher (also Playing Against Type)