A Labrador retriever named Quill begins specialized training as a guide dog from an early age, then the canine is paired with a blind man who is initially reluctant to rely on his new partner.
| Actor | Role |
|---|---|
 Kaoru KobayashiMitsuru Watanabe | Mitsuru Watanabe |
 Kippei ShiinaSatoru Tawada | Satoru Tawada |
 Teruyuki KagawaIsamu Nii | Isamu Nii |
 Keiko TodaMrs. Watanabe | Mrs. Watanabe |
 Tomoka KurotaniNot listed | Not listed |
 Kozo SatoNot listed | Not listed |
 Taro IshidaNot listed | Not listed |
| YYukika SakurataniMitsuko Watanabe | Mitsuko Watanabe |
 Yūko NatoriNot listed | Not listed |
 Kenji MizuhashiYuichi Sakai | Yuichi Sakai |
 Shinobu TerajimaMitsuko Nii | Mitsuko Nii |
| KKazu MatsudaEtsuo Watanabe | Etsuo Watanabe |
| HHiroko NatoriRen Mito | Ren Mito |
| RRafieAdult Quill | Adult Quill |