Mahou no Mako-chan (officially titled Maco the Mermaid by Toei in English) is an early Magical Girl Anime loosely based on The Little Mermaid, created by Toei Animation's planning team and veteran screenwriter Masaki Tsuji.
Mako is a young mermaid who one day rescues a handsome young man named Akira from drowning in a shipwreck and promptly falls in love with him. In order to be with her beloved, she convinces the Witch of the Sea to turn her into a human, becoming Ordinary High-School Student Mako Urashima.
The rest of the series follows Mako in her new life on dry land as she makes friends, learns about the human world, and solves problems with the help of her magical pendant given to her by her dad, Ryuu-oh the King of the Sea.
Made in 1970-71, Mahou no Mako-chan was the third entry in Toei's "majokko" series and the first to not be based on an existing manga. Along with contemporaries Attack No. 1 and Nozomi in the Sun, it's also one of the first anime made to appeal specifically to teenage girls, specifically viewers of Sally the Witch and Himitsu no Akko-chan who were maturing into adolescence. It suffered from mediocre ratings and is now considered one of the more obscure entries in the magical girl canon, but still has a devoted fan base - particularly in Europe and Latin America, thanks to its Italian, Spanish, and French dubs - who consider it a classic.
- Big Friendly Dog: Episode 32 has Lulu, a Saint Bernard who only ever gets angry when she protects her blind owner from being abused by her father.
- Bittersweet Ending: Mako and Akira do end up together, but Mako gives up her pendant as well as her life as a mermaid forever.
- Body to Jewel: Mako's tear, which turns into a magical pearl.
- Coming of Age Story: For Mako, who not only has to search for her guy, but also has to adapt to human life.
- Composite Character: The Sea Witch herself is Mako's grandmother, as opposed to have them be separate characters, like in the original fairy tale.
- Deranged Animation: When Mako first turns into a human, the visuals turn all trippy and nightmarish.
- Dub Name Change: In the Italian dub, Mako is Ginny and Akira is Alex. She's still Mako in the French and Spanish dubs, but the spelling is changed (to Makko in French and romanized to Maco in Spanish). Toei also officially spells Mako's name as "Maco" in English. Most of the other character names were changed in French, including Akira to Anthony and Tomiko to Isabelle.
- Godiva Hair: Unlike her Disney counterpart, Mako does not wear a seashell bra.
- Happily Adopted: Mako and her human foster family.
- Heel–Face Turn: Tomiko sort of has one, she stays a Rich Bitch but halfway through the series finally loses interest in Akira and stops being Mako's rival over him, and by the end of the show can be considered something of a friend.
- Identical Stranger: We meet a girl who looks like a blonde Mako in episode 13. She's murdered, though. In a subversion, this happened in a movie. The King was watching it and thought the actress was killed for real. Understandable, it looked like this was the first time he saw a movie.
- There's also Midori in episode 21.
- Lingerie Scene: A Trope Codifier in regards to anime. While not as salacious as the later Cutie Honey or Majokko Meg-chan, it was the first magical girl series to put the heroine in a Ms. Fanservice position, as it also features bathtub scenes and Mako wearing revealing clothing such as two-piece bikinis, miniskirts and see-through nighties.
- Parasol Parachute: One of Mako's rivals is a Creepy Child who uses his red parasol this way when he jumps off a building and escapes from her.
- Parental Fashion Veto: Ryuu-oh does *not* approve of his daughter wearing a two-piece bikini, and uses his magic to transform it into an old-fashioned one-piece. Mako changes it back.
- Princess Protagonist: The heroine Mako is a mermaid princess who is turned into a human but retains some magical powers in the human world.
- Rescue Romance: Genderflipped, Mako is the one doing the rescue. In the final episode, it nearly costs her her life.
- Reused Character Design: Mako bears a passing resemblance to Kozue Ayuhara from Attack No. 1.
- Urashima is the name of the main character in a Japanese folk tale, who saves a turtle and gets to visit a kingdom underwater.
- Makoto Kino (Sailor Jupiter) in Sailor Moon may be a Shout-Out to this series itself, as she's also known as "Mako-chan" to friends, she's also a brunette who wears her hair in a ponytail, and in one scene wears an outfit almost identical to Mako's civilian garb.
- Swiss-Army Tears: Mako turned into a human by swallowing a pearl that formed from one of her tears.