| Seiyuu | Role |
| Toshiyuki Morikawa | Naoto Kirihara |
| Akira Ishida | Naoya Kirihara |
| Akeno Watanabe | Shouko Futami |
| Hidetoshi Nakamura | Kyoujirou Mikuriya |
| Youji Ueda | Old Misaki |
| Akeno Watanabe | Naoto Kirihara (as a child) |
| Yuki Masuda | Naoya Kirihara (as a child) |
| Madoka Kimura | Miki Tachibana (Episode 1 - 4, 8) |
| Hideo Ishikawa | Jin Tanaka (Episode 2, 12, 13) |
| Yuko Nagashima | Reiko Hirose (Episode 2 - 4) |
| Misa Kobayashi | Mariko (Episode 3, 6, 12, 13) |
| Kouji Yusa | Tsukasa Kamiya (Episode 8 - 13) |
| Asako Dodo | Sachie (Episode 8 - 10) |
| Yurika Hino | Kanako Kurahashi (Episode 9 - 11) |
| Hiroshi Yanaka | Sonezaki (Episode 11 - 14) |
| Takanori Hoshino | Y (Episode 8 & 12) |
| Yasunori Masutani | Naoto's Father (Episode 1, 5, 6, 8) |
| Takashi Matsuyama | Mitsuo Hanaoka (Episode 5) |
| Yuka Inokuchi | Ayane (Episode 5) |
| Eri Kitamura | Taniguchi (Episode 6 & 7) |
| Atsuko Yuya | Yamashita (Episode 6 & 7) |
| Wataru Hatano | Yukio Izumi (Episode 6 & 7) |
| Misa Kobayashi | Takiko Yanokuchi (Episode 7) |
| Misa Kobayashi | Yumiko Futami (Episode 8) |
| Shigeru Shibuya | Sakaguchi (Episode 11) |
| Yuko Kaida | Mayumi (Episode 13) |
| Madoka Kimura | Saori (Episode 13) |
| Chihiro Suzuki | Alpha (Episode 14) |
| Daisuke Ono | Beta (Episode 14) |