Hime-chan no Ribon

Parareru, Parareru, Hello, Insert Name Here ni naare!

Nonohara Himeko is a magical tomboy of the cute witch type who can transform into anybody in the human world for one hour. This is due to her getting a magic ribbon from her alternate universe counterpart Erica, who just happens to be a princess in The Magical Kingdom. For one year, Hime-chan is allowed to use the ribbon as she sees fit - she agrees to it, so there's no room for I Just Want to Be Normal. There are a few limitations, however:

If she does not turn back to normal before the hour is up, she is stuck that way until she dies.
The person into whom she transforms is still in existence.
She needs to have some way of seeing herself in order for the magic to work.
The ribbon only works on humans.
No more people are allowed to learn about the ribbon's power.
You say the incantation backwards to reverse the transformation.
Stopping Time really messes up the ribbon's internal timer.

Her (not) boyfriend is Kobayashi Daichi, and he learns her secret due to her saving their collective asses from a kidnapper. Another not-boyfriend of hers is Arisaka Sei, who just happens to be Erika's ex-fiancee, Sei Arei. Nobody else is allowed to know under the threat of memory erasure for everyone involved. Which, while that would help the rival, Hibino Hikaru, in some ways, would not keep Hime-chan and Daichi from being together. Now if only someone could explain that to her so that she would stop almost discovering the secret...

Currently^[when?] fansubbed by the Honobono group, up to episode 21. Historically fansubbed to completion by Tomodachi in the days of VHS.

A remake manga entitled "Hime-chan no Ribbon Colorful" ran in Ribon, the same magazine where the original manga appeared, from 2009 to 2010.

Tropes used in Hime-chan no Ribon include:

All Girls Want Bad Boys - or at least Hime-chan and Hikaru do. Whether they know it or not, in Hime-chan's case.
Animal Eye Spy: Sei Arisaka has this ability.
Bathtub Bonding: Hime-chan and Pokota do this in episode seven when wondering what to do with Daichi knowing her secret.
The Beast Master: Sei Arisaka, can simply tell them what to do and they'll do it.
Be Careful What You Wish For - Hikaru, in the last episode.
Berserk Button - Pokota's not a cat, he's a LION!
The Bet: Sei Arisaka's driving force for trying to steal Hime-chan's ribbon was all over a bowl of ramen.
Bland-Name Product - Beginning with the opening credits, even!
Bokukko - inverted; Daichi Kobayashi expects Hime-chan to refer to herself as "boku" due to her boyish appearance and behavior, and is surprised when she uses the female-exclusive "atashi."
By the Power of Grayskull - the quotes at the beginning and end of this page, among others that come up later in the show.
Calling Your Attacks: SPECIAL HIMEKO KICK!
Cannot Spit It Out - Hime-chan, in later episodes. She lampshades this about her crush on Kouichi at the start of the show.
Can't Stand Them Can't Live Without Them - Hime-chan, Daichi, Sei, Hikaru, and Erika - how badly really depends on which dynamic you're looking at.
Christmas Episode
Covert Pervert - Hime-chan and I-chan.
Crash Into Hello - in Sei's first appearance, he gets hit by Hime-chan's schoolbag.
Cute Bruiser - Hime-chan is a terror on the soccer field.
Cut Short - Has an unusual (for anime) episode count of 61. In-show evidence suggests that it was supposed to have 78 episodes, but it wound up with a rushed and abrupt ending.
- This troper theorizes that the popularity of a certain other anime that was airing at the same time rendered "old-school" magical girl anime such as HCR passé, leading to a decline in Ratings.
Death Is Cheap - as it turns out, death is a cheap way to escape the eternal consequences of ribbon misuse. Because while being stuck in a transformed form is permanent and can't be undone by any magic, apparently the same doesn't apply to death.
Different As Night and Day - Hime-chan eventually acquires the ability to create a duplicate of herself. The duplicate (referred to as "Himeko" for distinction) is soft-spoken, polite, and feminine, unlike Hime-chan.
~Don't Try This At Home~ - variation; the opening animation was changed to remove shots of Hime-chan and Daichi riding double on a bicycle, after parental complaints that the series was setting a bad example.
- This is actually Lampshaded in the show - every time they ride double, they pass a guard that yells at them for riding double.
Dynamic Entry: "Hime-chan KICK!!"
Everything's Better with Princesses - Erika is the princess of the Magic Kingdom. This does not stop her from having to follow rules or face... consequences.
First Boy Wins - No matter how hard Sei tries to win Hime-chan's heart, or Hikaru to Daichi, Hime-chan and Daichi meet each other before any other plausible love interest combination appears.
First-Name Basis - it takes a while, but Hime-chan, Daichi, and "Arisaka" know each other on a first name basis by the thirteenth episode.
Forgotten Phlebotinum - the time-reversal magic would've been very useful on at least one occasion where Hime-chan completely forgets about it.
Full House Music - one of the piano pieces in the soundtrack is used this way.
Gender Vocabulary Slip - Hime-chan saying "I'm in the same middle school" leads to Daichi suddenly realise she's a girl -- she uses the female-only "atashi"
Genki Girl - Hime-chan; she's explicitly called this by her peers and some of the Fansubs even leave "genki" in the translations.
Hair Reboot - Partially with Erika. While it isn't immediate, upon returning to the Magical Kingdom, Erika's hair regains its original length gradually, going from Hime-chan's short boyish cut to her original length over the course of about 3 episodes.
Hand Behind Head: Very frequently. Do not watch this anime while playing a Drinking Game that looks for this.
Heroic Bystander: The truck driver who helps rescue Shintaro in episode seven, though he does faint at the gun-tooting kidnapper, he does instantly decide to search for the missing child.
Hit Me Dammit: Hime-chan says this to Daichi in episode 12 because she felt guilty about slapping him.
Honorifics - the usual ones show up, but note the scenes where Hime-chan's underclassmen in the theatre club refer to her as "Hime-chan-senpai," an unusual construction that displays conflicting interests of friendliness and respect.
- Arisaka gets called "Sei-sama" by his Instant Fanclub on his first day at the school.
Important Haircut - Erika gets one of these when she switches places with Hime-chan.
Incredible Shrinking Girl - Hime-chan, once she acquires the ability to increase or decrease the size of things. Since she is trying to keep things secret, we don't see much of the growth ability.
Instant Fanclub: Kouichi and Daichi have fanclubs within the school. When Sei transfers to the school he gets a club on the first day, with Daichi's fan club breaking up that day because they all left to join Sei's club. The club reforms after he leaves.
Intrepid Reporter - Hikaru teams up with one of these in an attempt to expose Hime-chan's secret.
I Want My Beloved to Be Happy - Hime-chan loves her senpai. Hime-chan's older sister also loves Hime-chan's senpai. Hime-chan's senpai loves Hime-chan's older sister. Hime-chan has to play matchmaker. This all just buildup to Daichi learning about the secret...
Jerk with a Heart of Gold - Sei Arei.
Late for School - Complete with the toast thing. Inverted when Hime-chan has to go to school early, and everyone at her house panics and thinks that they all overslept.
Lawyer-Friendly Cameo - Only in the manga. The anime really did have the advertised Idol Singer Group, SMAP, come and do vocals. Of course, since one of the members of SMAP was doing voice acting for the show to begin with...
Lethal Chef - Hime-chan's cookies make little girls cry.
The Little Shop That Wasn't There Yesterday: Sei's house, it vanishes when he leaves.
Living Toys: Pokota is one after Hime-chan gets the ribbon. Level 4 on the scale.
Magic A Is Magic A - most of the time it is, but cheap loopholes get exploited on occasion.
Magical Girl - Of the Cute Witch type.
Magical Girl Queenliness Test: A variation. Erika created the ribbon, and Hime-chan must use it for one year to determine whether it is useful, and consequently, if Erika will prove herself worthy to inherit the crown.
Magical Land
The Masquerade - Nobody else is allowed to learn about what Hime-chan can do. Memory loss is an effective deterrent.
Meaningful Name: Hime-chan, Aiko, Yumeko, and Hanako (their mom). Hime = Princess, Ai = Love, Yume = Dream, Hana = Flower.
Men Don't Cry - Gender Flipped with Hime-chan, because of her tomboyishness, and only when other people are around.
Mistaken for Gay: Yumeko is convinced that Erika is Hime-chan's girlfriend.
Most Writers Are Writers: Himeko's mother is a writer who likes to take the real life ideas and use them in her stories.
New Transfer Student - Sei in his second appearance. His first appearance did not explain his presence in any context.
Non-Human Sidekick - Hime-chan's stuffed lion, Pokota. Also Erika's broom, Chappy.
Offhand Backhand - Sei's first appearance.
Onee-Sama - Aiko is Hime-chan's much-admired older sister.
One Head Taller
Only Six Faces - it's lucky that everyone in the Magic Kingdom looks exactly like someone in the human world.
Panty Shot - averted. Not only are there no pantyshots for the audience when Hime-chan plays soccer in her school uniform, at one point one of the male players specifically says, "No, don't do it! We'll see your panties!"
Potty Failure - Yumeko has an accident and wets her bed in one episode of the anime version
Recap Episodes - Six of them within the last seventeen episodes. They're all in pairs too, which makes getting through the last quarter of this anime a chore.
The Rival - Hikaru Hibino, although Hime-chan often doesn't acknowledge her.
Secret Diary - Aiko finds Hime-chan's diary, and from it she finds that Hime-chan had feelings for Hasekawa.
Secret Keeper - Daichi.
Shoujo
She Is Not My Girlfriend / He Is Not My Boyfriend - Daichi & Hime-chan. Maaany times.
She Knows Too Much - Himeko's Mother wrote a book. The events of the book were duplicated within the show against her. Please note that this is what leads to the earning of the growing/shrinking power.
Stable Time Loop - when Hime-chan visits her future self. No consequences to the main plot.
Talking To Herself - Hime-chan, Erika, and Hime-chan's duplicate are all played by Ikue Ohtani, whom you might better know as a "shocking" yellow mouse.
Takehito Koyasu - as Sei Arei.
Tech Marches On - The frequent use of landline phones and pay phones is very noticeable to late 2000s audiences.
- Hanako's (Hime-chan's Mother) computer is also very noticeable compared to modern computers.
The Show Must Go On - Hime-chan's magically-arranged SMAP "appearance" at the school.
Third Person Person - Yumeko, although strictly speaking she refers to herself as "Yume" rather than "Yumeko."
Time Stands Still - Hime-chan acquires this ability, with all its unexpected consequences.
Tomboy - take a wild guess.
Transformation Sequence - visibly lacking in Fan Service.
Transformation Trinket - the titular Ribbon. Does not work on non-humans. Members of the Kingdom of Magic do not count as humans.
Twin Switch - Hime-chan and Erika pull this off after Hime-chan gets stuck as Hikaru Hibino for a few episodes.
Twin Telepathy - Erika and Hime-chan share a bit of this.
Unlucky Childhood Friend - one of Daichi's.
Verbal Tic - Chappy the Broom's "*swish*swish*".
Wouldn't Hit a Girl: Daichi says this when Hime-chan asks him to hit her in episode 12 because she felt guilty about slapping him.
Zettai Ryouiki - Hime-chan is B-Class.

Lulerapa, lulerapa, moto no sugata ni naare!