Nagasaki in 1986. Young friends Hisada and Takemoto decide to go to Boomerang Island to "see the dolphins". The friendship between the two deepens as a result of this adventure.
| Actor | Role |
|---|---|
| IIchiro BankaTakaaki Hisada (young) | Takaaki Hisada (young) |
 Konosuke HaradaKenji Takemoto (young) | Kenji Takemoto (young) |
 Machiko OnoRyoko Hisada | Ryoko Hisada |
 Tsuyoshi KusanagiTakaaki Hisada | Takaaki Hisada |
 Pistol TakeharaHiroshige Hisada | Hiroshige Hisada |
 Shihori KanjiyaMasayo Takemoto | Masayo Takemoto |
 Ryo IwamatsuUchida | Uchida |
 Eri MurakawaYayoi | Yayoi |
 Momoko FukuchiAko | Ako |
 GorikenTakeo Ouchida | Takeo Ouchida |
 Rintaro HachimuraKanayama | Kanayama |
 Mizuki KayashimaYuka | Yuka |
 Atsushi ShinoharaManabu Miyata | Manabu Miyata |
 Yuki IzumisawaIchikawa | Ichikawa |