There is a legend in Japan that if one eats the flesh of a mermaid, one will become immortal. This anime recounts the story of Yuhta and Mana, an immortal boy and girl, and their experiences with a family struggling to achieve immortality at any cost.
| Actor | Role |
|---|---|
 Koichi YamaderaYuta (voice) | Yuta (voice) |
 Minami TakayamaMana (voice) | Mana (voice) |
 Mika DoiTowa Kannagi (voice) | Towa Kannagi (voice) |
| AAiko KonoshimaSawa Kannagi (voice) | Sawa Kannagi (voice) |
 Ryuji SaikachiDr. Shiina (voice) | Dr. Shiina (voice) |
 Kazumi TanakaShiina (young) (voice) | Shiina (young) (voice) |
 Wakana YamazakiSawa Kannagi (young) (voice) | Sawa Kannagi (young) (voice) |
 Ginzo MatsuoBarker (voice) | Barker (voice) |
 Toshio KobayashiSoldier A (voice) | Soldier A (voice) |
 Hikaru MidorikawaSoldier B (voice) | Soldier B (voice) |
 Masaharu SatoPolice A (voice) | Police A (voice) |
 Kazuo OkaPolice B (voice) | Police B (voice) |
 Yoshio KawaiCaptain (voice) | Captain (voice) |