Masaharu "Haru" Tsuwabuki is an introverted Ordinary High-School Student. After going about things as usual he bumps into a masked figure and accidentally picks up a dropped potion of theirs, later drinking it thinking it to be soda. He then finds himself transformed into a lamb, and must collect seven stardrops to return to normal.
Nanatsuiro Drops ("Seven-Colored Drops") is a Visual Novel developed by UNISONSHIFT and released on April 21, 2006. First available on the PC, the game contained adult-only content. It was later ported to the PlayStation 2 by Media Works and released with additional characters but without the adult content on September 20, 2007 under the title Nanatsuiro Drops Pure!!. A similarly censored version for the Nintendo DS was released on May 15, 2008.
Shortly after a Light Novel was adapted from the work written by Tamaki Ichikawa and illustrated by Noizi Ito, published by Enterbrain on June 30th 2006.
This was quickly followed with a Seinen Manga adaptation created directly under UNISONSHIFT and illustrated by Yūki Takami first published by Media Works in September 30th in Dengeki G's Magazine with an ongoing run, currently totaling three volumes. A second Shōnen Manga adaptation also produced under UNISONSHIFT was made under the title Nanatsuiro Drops Pure!! illustrated by Sorahiko Mizusima and again published by Media Works this time in Dengeki Comic Gao!, running from April 27, 2007 to February 27, 2008, culminating in one volume.
Finally, a twelve-episode TV anime was produced by Studio Barcelona under director Takashi Yamamoto with an original run from July 2, 2007 to September 30, 2007. The opening theme is "Shining stars bless☆" by Kaori Utatsuki, and the ending theme is "Mo・o!" by Loverin Tamburin.
An Internet radio show called Nanatsuiro Radio! was also based on the work, starting on April 6, 2007, and published by Media Works.
The anime provides examples of:
- Beach Episode: Episode 4.
- Blush Sticker: These seem to be an actual part of Yuki-chan's face.
- The Cameo: The PS2 port features a brief crossover with Shakugan no Shana, as both works are illustrated by Noizi Ito and published by Media Works. The scene itself features Haru and Mei encountering Shana, Yuji, and Alastor as they are eating ice cream.
- Chromatic Arrangement: Sumomo (pink), Nako-chan (green), and Nona (blue).
- Curtains Match the Window: Pretty much everyone besides Flora and Prima Asparas, both being blue-eyed blondes.
- First Girl Wins: Sumomo is the first girl we see. She and Haru end up together.
- First Kiss: Sumomo and Haru have theirs in episode 8.
- Gotta Catch 'Em All: Whoever gets 7 Stardrops first wins.
- Huge Guy, Tiny Girl: Haru is very tall, while Sumomo is very short.
- Idiosyncratic Episode Naming: Every episode name has the word "color" somewhere in it.
- Kimodameshi: In episode 5.
- Large Ham: Arthur Matsuda.
- Laser-Guided Amnesia: The price of giving Haru the potion that makes it so he won't turn into Yuki-chan again is that he won't have any memory of the past six months. Meaning pretty much everything from just before the start of episode 1.
- Luminescent Blush
- Lunacy: On a new moon, Haru will stay human for the whole day. On a full moon, Haru will remain as Yuki-chan for the whole day.
- MacGuffin: The Stardrops.
- Magical Girl
- Meet Cute/Crash-Into Hello: Sumomo and Haru. They bump into each other and Sumomo drops her watering can, which gets Haru all wet. Sumomo starts crying, and Nadeshiko runs over, sees Sumomo crying, and pretty much threatens to kill Haru.
- Meganekko: Nona Yuuki. She only needs them in civilian form, apparently.
- Missing Mom: Sumomo's mom is apparently working overseas, or something.
- Nerd Glasses: Haru's friend Keisuke.
- Official Couple: Haru/Sumomo.
- The Ojou: Nona.
- Only Known by Their Nickname: Nako-chan's full name is Nadeshiko Yaeno. Anyone who doesn't call her 'Nako' calls her 'Yaeno'.
- Punny Name: In Japanese 'Yuuki Nona' can be written as organic vegetables.
- Rapunzel Hair: Nona and, to a lesser extent, Nako-chan
- The Rival: Nona Yuuki.
- Secret Keeper: Nadeshiko.
- Shipper on Deck: Pretty much everyone in regards to Haru/Sumomo.
- Shrinking Violet: Sumomo.
- Transformation Sequence: An odd case in that they wait until the ninth episode to give her one, and then we see it exactly twice.
- 12-Episode Anime
- I Want My Beloved to Be Happy: If Sumomo wasn't chosen in the game.
- You Gotta Have Blue Hair: Sumomo (pink), Nako-chan (green), Nona (blue), and Nobuko (literal red).
- "For example, when looking at the stars outside the window. For example, when writing in the secret journal about the day. Mysterious things suddenly fall down from the sky. The key to everything are the Stardrops that fall from the sky, and a special girl. It is a magical story of 'a seven-colored first love that encompasses you.'"