Wow, that is the most creative way/entertaining way I have seen to add a mermaid waifu to the group. The funny thing is using appendages to catch fish actually works and is something people and animals do. And fly fisherman routinely use fur with their lures.
For example:
Well I can now add fluffy loving mermaid, alongside skeleton oneesan lady to my fantasy/isekai list of archetypes. It's rare for a series to have two unique differences like this. Fenrir is pretty much mandated, and I have seen a number of insect queen's before.
Guess now i understand why the Series isn't labelled Harem yet.
Because there is only one possible girl for MC (Undead girl is not possible because she is all bones, and I don't think the Mermaid girl would be go after MC, as she seems childish).
I agree and also dont think this series is headed towards romantic Harem.
But I then there is rule 36. Rule 36 is if something can be made due to rule 34, then it can be a viable romantic love interest. So undead skeleton lady is certainly possible. As for why we don't mention rule 35, is because that is where rule 34 goes to figure out the mechanics of how to make things viably work.
Rule 36 in Japan is known as the first law of waifu. If it's female, it can be a waifu. It doesn't matter who or what the main character is. Can be undead, non sentient, or even a vending machine(as seen in new/upcoming anime adaptation).
Obviously I am making up a bunch of terms and joking a bit. Just a bit. Rule 34 is a real thing, and I am sure you could find examples where people already made it work with skeleton women. I'm not going to search myself, as I value my remaining brain cells and sanity. For this series though, the fact skeleton lady can transform/use magic means it is entirely possible for the author to make her a ship down the road.