At the end of Book 3 Azul explains, “Betentacled mermen like myself aren’t common around these parts.”
He offers this information in response to Grim asking why he has opted to remain in human form while visiting the museum, saying that he does not want to attract “any undue attention.”
The dialogue on EN might sound a little vague: does “betentacled” mean that there are other mermaids with tentacles, like squid, that are similarly uncommon?
But Azul’s original line is “僕のようにタコ足の人魚はこの辺りではとても珍しい”, which literally translates closer to “Mermaids like myself with octopus legs are unusual in this area,” so it seems he does mean octopus specifically.
Azul specifies “around these parts/in this area” in both the original game and the English-language adaptation, which is interesting.
Are there other areas in the Coral Sea where octopus mermaids are more common and he would not stand out? Or are they more often found in a different ocean entirely? Did Azul’s family migrate from somewhere else originally, or have they always lived there?
Twisted Wonderland Reference Note 