Neptina is a young mermaid who appears in the anime Ganbare! Marine Kid. Her name was altered from Neptuna when the series was expanded from the earlier pilot Dolphin Ouji. She has long flowing hair and a yellowish green tail, and she serves as a loyal ally to the protagonist Marine Kid and the Ocean Patrol.

As a mermaid, Neptina possesses natural abilities that aid her in underwater environments. She carries a large magic pearl that she uses to locate Marine Kid whenever he is lost or captured by enemies. She also has the ability to communicate with sea creatures, which allows her to gather information or summon assistance during missions. Her role in the story is primarily supportive: she assists Marine Kid in his adventures, often providing crucial magical or navigational help when technology or direct combat are insufficient.

Neptina is portrayed as a good friend and teammate to Marine Kid. She works alongside other recurring characters such as Splasher the white dolphin, and she is part of the broader cast that supports the Ocean Patrol’s efforts to protect the seas. Her motivations are rooted in friendship and the desire to keep the underwater world safe from various threats.

Information about Neptina’s personal background, inner personality, or character development beyond her role as an ally is limited. She appears consistently as a helpful presence, and her interactions with Marine Kid and other characters reinforce her loyalty and resourcefulness. Her magic pearl and ability to speak with sea creatures are the most notable of her abilities, making her an indispensable link between the human heroes and the mysteries of the deep.