Nana Suzuki is an ordinary schoolgirl with a crush on one Yuichi Kamichika. One day, while trying to bake a cake for Yuichi, she stumbles on her scientist grandfather's secret experiment to separate the light of a rainbow into seven crystals. Naturally, the experiment goes awry, and splits Nana into seven versions of herself, each with her own matching rainbow crystal. Now, Nana must find a way to integrate the crystals together, or else all seven of her will vanish.
The Seven Nanas are:
- Nana: The Original, or possibly the Responsible Nana. She uses the blue crystal.
- Nanappe: The Bokukko Nana. She uses the red crystal.
- Nanakko: The Slacker Nana. She uses the orange crystal.
- Nanacchi: The Cheerful Nana. She uses the yellow crystal.
- Nanarin: The cry-baby Gamer Chick Nana. She uses the yellow-green crystal.
- Nanasama: The Bookworm Nana. She uses the green crystal.
- Nanapon: The Weird Nana. She uses the purple crystal.
Not the be confused with the manga/anime Nana.
This show features these tropes:
- Balloon Belly: Nana in the DVD episode.
- Book Dumb: All of the Nanas, save Nanasama.
- Bungling Inventor: Nana's grandfather.
- Cloning Blues
- Color-Coded for Your Convenience: The seven Nanas.
- Crossover: Mutsumi and the Hinata's house ghost, who had already appeared in the Sgt. Frog manga, made their first animated appearance in the Seven Of Seven anime.
- On the other hand, Melody Honey, who debuted in this series, goes on to appear in both Sgt. Frog and Arcade Gamer Fubuki.
- The Dividual: In addition to the main character(s); her classmates Megumi Hayashiba, Erino Kogarashi, and Motoko Morinuma are often together and speak at the same time.
- Evil Twin: An eighth Nana, Jamanana. In the manga, Nanacchi, of all the Nanas, was the mean one.
- Fanservice: Interestingly, the series is not too Fanservice-ey until the very last episode 26, "Its New Years!7x7=49 Nanas?" which had Overnight Age-Up and Clothing Damage
- Flight: The Nanas can fly.
- Henshin Heroines: Their crystals turn a group of Sentai costumes in legitimate Nanaranger suits.
- Hive Mind: The six other Nanas tend to act as one person.
- Hotter and Sexier: The manga.
- Hypno Pendulum: Nanapon used her prism as one of these in an episode. She even accidentally hypnotizes herself when trying to teach the original Nana how to perform hypnosis.
- Light 'em Up: Teardrop Spectrum
- Literal Split Personality
- Me's a Crowd
- Numerical Theme Naming: Not only does Nana's name translate to "seven" in Japanese, but her family members also have names that partially include words or kanji that also mean numbers: Her mother is Mitsuko (mitsu is a counter meaning 3), her father is Goro (go means 5), and her grandfather is Rokuzo (roku is 6). Even the boy she has a crush on, Yuichi, has a number in his name (ichi is 1).
- Rainbow Motif: With indigo switched out for yellow-green.
- Red Oni, Blue Oni: Nanappe is hot-tempered, violent, and wields the red crystal. Regular Nana is much more calm, rational, and level-headed, and wields the blue crystal.
- Sentai: The seven Nanas can become the seven Nanarangers.
- Snow Means Love: Valentines Day was very snowy in the first episode.
- Two Girls and a Guy: Nana, Hitomi, and Yuichi in the manga, where the three are childhood friends.