Meroune's Mother

Meroune's Mother (メロウヌの母親, Merōnu no Hahaoya) is the currently unnamed mother of Meroune Lorelei. She is also the current Queen of the Mermaid Kingdom.

Appearance
As the current mermaid queen, Meroune's mother has an incredibly regal appearance, consisting of an elaborate headpiece and necklace, a frilly skirt and trail, and long hair styled in several thick, tightly wound curls. She is also seen wielding a long trident.

Personality
Of all the main characters' parents that have been encountered so far in the series, Meroune's Mother is by far the most twisted and morally reprehensible encountered in the story so far. At first glance, Queen Lorelei seems like a stern and reserved ruler who bases her decisions on what is best for the Mermaid Kingdom  without letting her personal sentiments cloud her judgment. She is later revealed to be a self-absorbed and dangerously immature tyrant who prioritizes her own passions at the expense of her family and her people. This is glaringly illustrated when she secretly engineers a diplomatic crisis with the human world to set the stage for the "perfect tragedy" and nearly murders Kurusu to punish her daughter for desiring eternal happiness with him.

After Mero nearly died saving Kimihito's life she abandoned most of her desires for tragedy, as almost losing her daughter showed her that tragedy was not all it is supposed to be, and publicly dispels rumors surrounding Oct and a human elopement problem. However, she notably refrains from admitting her responsibility in engineering such rumors and ultimately evades punishment for her misdeeds.

Skills and Traits
Diplomacy: As the ruling monarch of the mermaid species, Meroune's mother is presumably skilled in diplomacy. Her reign coincides with mermaids starting to take part in human society under the Cultural Exchange Between Species Bill, implying that she has some experience dealing with human governments.

Manipulation: The mermaid queen is quite skilled at manipulating events so that they play out to her desires. The entire situation involving Oct, the mermaid elopment problem, and decline in human-mermaid relations were all the result of her machinations to create "the Ultimate Tragedy". Her abilities to manipulate events are not perfect as she was unable to stop things from spiraling out of control when her plans were uncovered, but she was still able to avoid any punishment by misdirecting and misinforming the entire Mermaid Kingdom.

Plot
Meroune's mother's first interaction with the members of the Kurusu House was when she had Sabastian and Potemkinme hire TALIO to accompany Mero back to the Mermaid Kingdom from her onsen trip with the rest of the girls and Kimihito. Upon talking to Mero she informed the young mermaid that she could not return to human society with her friends, as "human-mermaid relations were not well."

When her daughter returned to her to clear Oct's name, the queen revealed that she was the one spreading the rumors about Oct. Her motiviations were that she wanted to ruin the relationship between humans and mermaids so that her human lover would have to leave and she would be unable to follow him because of her duties as queen, creating what she considered "The Ultimate Tragedy". Upon hearing this Mero was upset that her mother was cheating on her husband, but the queen revealed that she had been doing so for years and it is part of the reason the king ran off.

Mero's mother then accuses Mero of not loving tragedy anymore and that she would make her remember it by causing Kimihito's death. The mermaid queen used a tablet device to start flooding the room they were in so that Kimihito would drown. Mero asked her mother to spare Kimihito's life as she wanted to have a "happily ever after story" with him. The queen agreed to save his life, but only if Mero would return home, to which Mero agreed even if it meant leaving Kimihito. However, when Mero's mother tried to drain the room she found the tablet device had been damaged, causing the ceiling to collapse, strong underwater currents, Fin Eater piranhas to appear, and for spikes to protrude from the bottom of the room.

Later after Mero nearly died saving Kimihito's life Mero's mother had a change of heart and decided to let Mero return to human society with her friends. She also broadcasted a message to the Mermaid Kingdom saying that there was no elopement problem and that human relations were fine, thus exonerating Oct of all crimes. She also introduced the kingdom to her human lover, but left out that all the rumors were her doing, as there would have been a revolt if anyone knew the truth.