Akeno is not only a mermaid, but also a "mermaid examiner". She has the responsibility of deporting all the mer-people who fail to qualify as not only resembling humans but also not arousing any suspicion of their true identities; and unlike the other mermaids in the cast, Akeno is capable of suppressing her mermaid transformation, for brief moments, after coming into contact with water, having trained herself to do so. When first introduced she had a hostile attitude towards the other major protagonists.
Akeno is not only a mermaid but also a "mermaid examiner". She has the duty to expel all mer-people who do not meet the criteria of resembling humans and not raising suspicion about their true identities. Unlike other mermaids in the cast, Akeno can temporarily suppress her mermaid form after coming into contact with water through training. When first introduced, she had a hostile attitude towards the main protagonists.