"Terebi Doga", wishing to further explore their "Dolphin Prince" concept via a full color version, returned to Fuji TV, expecting that the network would happily buy an expanded version of their original monochrome pilot series. Fuji, however, declined to buy into the project, happy as they were with the ratings they were achieving with their current Thursday night black and white anime series "Harris' Whirlwind" (ハリスの旋風 - "Harisu no Kaze"). Undeterred, "Terebi Doga" found external sponsorship from the Matsushita Company (later to be known as National Panasonic Matsushita), and sold their new version of "Dolphin Prince" to rival TBS Network. Character names were altered, (changing 'Dolphin Prince' to 'Marine Kid' and 'Neptuna' to 'Neptina'), characters were added and concepts expanded. In order to distance the new series from the original trial episodes, the series was re-titled "Hang On! Marine Kid" (がんばれ!マリンキッド - "Ganbare! Marin Kiddo") and aired on Thursdays at 7:00 pm between 6 October and 29 December 1966. Despite Toei Doga's high hopes, the scheduling of "Hang On! Marine Kid" was a ratings disaster for TBS, slotted as it was directly in opposition to the ever-popular "Harris' Whirlwind", which was still airing on Fuji TV at 7:00 pm. "Hang On! Marine Kid" was cancelled after its first batch of 13 episodes and not renewed.