Main Cast:
* Jun Hoshizora: Megumi Ogata
* Kenta Azuma: Toshiyuki Morikawa
* Kohei Shibata: Hikaru Midorikawa
* Kazuki Shibata: Hiroyuki Yoshino
* Ryouko Shibata: Miki Itou
Supporting Cast:
* Dr. Shibata: Kenyu Horiuchi
* Asuka Shibata: Yumi Touma
* Kaoru Shibata: Yumi Kakazu
* Goro Shibata: Kazuhiko Inoue
* Kyoko Shibata: Junko Minagawa
* Kenzo Shibata: Nobuo Tobita
* Taro: Eiko Hisamura
* Maria: Maria Kawamura
* Kyohei: Issei Futamata
* Genzo: Yasunori Matsumoto
* Ryo: Sho Hayami
This is just a partial list. There were many other actors and actresses who provided voices for various characters in the series.
It's worth noting that the English dub for "Steel Lady Jun" features different voice actors. You can find more information about the English cast online.