Kaido Minami

Kaido Minami (海藤みなみ Kaidō Minami) is a one of the main Cures of this season. She is a 14 year old girl and has a strong sense of responsibility as well as caring for others like an older sister. Minami's alter ego is Cure Mermaid (キュアマーメイド Kyua Māmeido), the Princess of the Sea.

Appearance
Minami has dark turquoise hair that is seen down with a thick strand of hair tied into a braid that is seen lying over her shoulder. Her eye colour is blue. She wears a light blue long-sleeved shirt with a lilac ribbon tied around her neck that rests just above her waist. Her shirt is tucked into a dark blue skirt and she wears matching shoes with pink bows on top.

As Cure Mermaid, Minami's hair grows drastically that is ocean blue on top with a dark blue ombre and light purple streaks on the bangs. She wears a golden tiara with a light blue ribbon and a pink and blue seashell attached to it. Her midriff top is blue and white with a light blue collar and white sleeves. Around her neck is a pink pearl necklace with a gold brooch at the center with more pink pearls lining down along the top. Her skirt is blue, light blue and pink with light pink pearls around the waist and is longer at the back. Her boots are knee-length and light blue trimmed in blue with pink pearls. She also wears very long light blue arm warmers that stop at her hands with pink pearls at the end and seashell earrings.

When she changes into her Elegant Mode, her skirt lengthens drastically and looks wave-like.

Personality
Minami is a sophomore at Noble Academy who is nicknamed as the 'Academy's Princess'. She has a strong sense of responsibility who can sometimes be strict as well but cares for others like a caring older sister. She dreams of becoming a respectable person who can be useful to others like her father and brother. In Episode 9 it is revealed that Minami is afraid of ghosts.

Transforming Into Cure Mermaid For The First Time
While looking over the sea one day, Minami discovers a Dress Up Key that had been washed up on to the shore. When Haruka sees Minami dancing ballet, she becomes inspired and hastily asks her to teach her how to do it. She helps her through the basic steps and tries to makes her more flexible. When Haruka sprains her ankle after trying to perform a new step, Minami comes to her aid and bandages it. Haruka is surprised to find out that Minami is not as perfect as she first thought, and she even thanks Haruka for asking her to teach ballet because no one else had the confidence to do so. When a Zetsuborg attacks, she follows Haruka and witnesses her transforming into Cure Flora. When Flora damages her ankle again after kicking the Zetsuborg, she is about to be attacked before Minami pushes her out of the way. When Flora takes a hit for her, Minami tells Close that it is her duty to protect the students of the academy. Her Dress Up Key reacts to her determination to help others and she receives her Princess Perfume, allowing her to transform into Cure Mermaid. She was able to fight the Zetsuborg off before purifying it with Mermaid Ripple.

Relationships
Haruno Haruka - At first, she told Haruka when she was late to the Welcome Ceremony to reflect on her actions. After that, Haruka asked her to teach her ballet and she agreed. They spent some time together when training. When Haruka sprained her ankle, Minami helps her and tells her how she's not perfect. When she saw Haruka transforming and having problems with the Zetsuborg, she tried to protect Haruka, which resulted in her becoming a Pretty Cure. They then became good friends.

Amanogawa Kirara - Even though Kirara still not very close with Minami, they do share a friendly relationship.

Kaido Wataru - Her older brother.

Cure Mermaid
"The princess of the crystal clear seas! Cure Mermaid!"

澄み渡る海のプリンセス！キュアマーメイド！

''Sumiwataru umi no purinsesu! Kyua Māmeido!'' Cure Mermaid (キュアマーメイド Kyua Māmeido) is the Pretty Cure alter ego of Minami. She controls the power of water and transforms with the phrase, "Pretty Cure! Princess Engage!". Her main attack is Mermaid Ripple, which she can only perform while in her Mode Elegant.

Attacks

 * Mermaid Ripple (マーメイドリップル Māmeido Rippuru) is Cure Mermaid's main attack, that can only be used when she is in her Mode Elegant.
 * Trinity Lumiere (トリニティリュミエール Toriniti Ryumiēru) is Cure Mermaid's group attack that she performs with Cure Flora and Cure Twinkle, where she needs the Crystal Princess Rod.
 * Frozen Ripple (フローズンリップル Furōzun Rippuru) is Cure Mermaid's main attack, performed with the Crystal Princess Rod. To perform this attack, she must be in her Mode Elegant Ice.

Etymology
Kaido (海藤): Kai (海) means either 'sea' or 'ocean' which is probably a reference to her name, "Mermaid", since mermaids live in the sea. Do (藤), read as "Fuji", means 'wisteria'.

Minami (みなみ) means 'south'. But it can also be read as "beautiful wave".

Therefore, Kaido Minami means "southern wisteria sea", "southern wisteria ocean", "wisteria sea beautiful wave" or "wisteria ocean beautiful wave".

Cure Mermaid means the legendary aquatic creature with the upper body of a human and the tail of a fish.

Trivia

 * Minami's birthday is July 20. Hence, her zodiac is Cancer.
 * Her birthday occurs on a Japanese national holiday, "Ocean Day" (海の日), of year 2015, which is probably due to the fact that her powers are based off the ocean.
 * Minami is the first blue Cure to have purple streaks and a dark blue ombre.
 * She is the third blue Cure to be a student council president after Minazuki Karen from Yes! Pretty Cure 5 and its sequel and Aoki Reika from Smile Pretty Cure!
 * She is the fifth student council president overall.
 * She also shares many similarities with Minazuki Karen and Aoki Reika.
 * They all have blue as their theme color.
 * They are the most intelligent Cure in their group.
 * They all have related powers. (Minami and Minazuki Karen's powers are water, while Aoki Reika's is ice, a form of water.)
 * All are part of the student council.
 * All of them have polite and calm personalities.
 * She is the only Go! Princess Cure to not wear gloves that cover her hands as well as not having a big, puffy skirt in her Elegant Mode. The reason could be to make her seem more like a mermaid.
 * She is the third blue Cure to have water powers, preceded by Cure Aqua from Yes! Pretty Cure 5/Yes! Pretty Cure 5 GoGo! and Cure Marine from Heartcatch Pretty Cure!.
 * Minami shares her surname with Kaido Yuya from Happiness Charge Pretty Cure!.
 * She is the fifth Cure to wear a midriff, preceded by Cure Black (in Futari wa Pretty Cure), Cure Dream (in Yes! Pretty Cure 5!),Cure Berry, Cure Sunshine and Cure Melody. She is also the second blue Cure to wear a midriff-baring top.
 * She is the third Cure or Cure-like character to have a braid in her hair in her civilian form, following Kujou Hikari and Hishikawa Rikka.
 * According to unspecified sources who also gave out the info of the Cures' names, Minami is based off the title character of the fairy tale The Little Mermaid by Hans Christian Andersen.
 * Minami's hairstyle is similar to Minazuki Karen's.
 * Her name 'Minami' is similar with Minamino Kanade's surname from Suite Pretty Cure! which also have the same meaning which is "south". "Minami" was also used as the surname of Soular's human alias, Minami Shun from Fresh Pretty Cure!.
 * She is the fourth Cure to be afraid of ghosts, following Natsuki Rin, Kurokawa Ellen and Midorikawa Nao.