Sonja's Adventures of The Little Mermaid is a story arc from Sonja's Adventures season 2. It was dubbed in four other languages and was aired worldwide in May 2017.
Minami Kiado falls in love with the reformed villain, Dr. Nefarious, but fears he will never love her due to a lack of fortune. When the Shadowlings kidnapped her instead of Sonja by mistake, Sonja and her friends will have to face their fears to save her.
Part One: The little Curemaid Edit
The episode begins with the Princess Precure being late to Sonja's concert due to Minami trying not to trip over her dress. Their leader, Haruka pesters her for being so late just as they approach the concert hall. When they arrive, Haruka tells Alister not to tell anyone that they were late as Minami walks by and wishes Alister a good day. For the concert, Sonja sings "Treasure huntin' fever" to fit the underwater theme.
After the concert, Sonja begins signing autographs from other fans, to them the Princess Precure come up to her and they wanted her autograph. Sonja complies, saying "Hi Haruka!" at the bottom, causing Haruka to fangirl and leaves the others irritated with her. Shortly after, Sonic and Cure Marine aka Erika along with her fairy Coffret talking about hanging out together sometime. Marine suggests the beach, but due to her aquaphobia, Sonic declines and leaves Erika sad and confused. Sonic looks out a nearby window saying that he does not want to admit his fear to Erika, who he worries will see him as a coward. Meanwhile, Ratchet is seen talking to his old pal Dr. Nefarious, who was invited to the concert, but does not feel comfortable with everyone. Minami then comes by as she leaves, but trips on her dress and ends up face-to-face with Nefarious. Minami stutters her words as Nefarious helps her up, but the romantic scene is broken when Minami is called back home, Nefarious instantly fell in love with Minami because he finds her enchantingly beautiful.
Some time later, Marine calls Sonic again for another hangout, this time at a lake in Sweets Kingdom, but Sonic declines again, leaving Erika disappointed. Marine is then called to the Princess Precure hall for the cures to discuss Minami's strange behavior before coming to the conclusion (through song and dance) that she is in love with someone. The groups head out into the town to get Minami to admit that she has a crush, but Minami refuses to say anything no matter how much her friends wear her down
Lost Ridge Monatana
Dr. Nefarious' lab
Crystal Merbax seas
Mystical world (Opening)
Chasing (Opening Japanese)
Treasure huntin' fever
She's in love!
I Won't Say I'm in Love
Kiss the girl
I'll treasure you
We are pop candy (Ending Japanese)