Isamu Koyama
Discography
| Date | Catalog | Name | Roles |
| 2006-08-09 | GNCA-7907 | Muteki na smile / Naozumi Takahashi無敵なsmile / 高橋直純Muteki na smile / Naozumi Takahashi |
|
| 2010-01-13 | AVCD-31603/B | Kaze wo Sagashite / Mari Yaguchi & Straw Hat風をさがして / 矢口真里とストローハットKaze wo Sagashite / Mari Yaguchi & Straw Hat |
|