|Season||Glitter Force Doki Doki|
|Eye Color||Dark Blue (Rachel)|
|Hair Color||Navy (Rachel)|
Blue Indigo (Diamond)
|Home Place||Seashell Bay|
|First Appearance||Episode 1 (Doki Doki) (Rachel)|
Episode 2 (Doki Doki) (Cure Diamond)
|Alter Ego||Glitter Diamond|
Cure Diamond (Japanese Dub)
|Theme Color||Blue (main)|
|Japanese Voice Actor||Kotobuki Minako|
|English Voice Actor||Cassandra Lee Morris|
Rachel has dark blue eyes and chest-length, navy-blue hair worn loose with a braid on each side of the head held back by a ribbon. Her bangs are layered in length to frame her face. She wears red glasses. She wears a white long sleeved blouse with crimped lines and ruffles at the middle, worn beneath a light blue pleat dress with a buttoned band beneath the chest and frilly petticoat. At the neck is a blue ribbon. She also wears black socks with brown boots. For summer she wears a white tunic with a light blue collar and skirt. Around the bottom of the dress is a sideways blue diamond pattern accenting her striped sleeve cuffs and the bow hanging from her neck. This is paired with white socks with a frilly cuff and black flats.
As Glitter Diamond her eyes and hair brighten in colour while her light indigo hair grows in length and is worn in a thick, high ponytail with a large curl on end, followed by four separate curled strands. Her ponytail is held by a blue hair piece lined in dark blue and trim with feathery fabric. A dark blue diamond rests on it to match her earrings. Her dress is sky blue with indigo lining the top of the chest and two strands of frilly fabric lining on the chest and shoulder. A white and indigo striped band is diagonally sewn at the corner with a blue ribbon on the right hip where her Glitter Pad rests. A sapphire gem heart with a white ribbon rests on the left of the chest. The white sleeves feature a single puff with a gold band around it, while the other resembles a small wing. The skirt of the dress resembles a pair of white wings and is spread open to reveal short white wing-shaped material that has a single line of sky blue on it. She also gains white boots with a sky blue opened cuff and a gold band to match her bracelets and choker.
Rachel is an intelligent girl who is often quiet, but she is blunt and not afraid to speak her mind. She loves to study and is one of the top ten scoring students in the national trial exams. As noted by Maya in episode 9 of the first season, Rikka is at the top of the class and constantly placed as the first place in her school, however, her scores started to drop as she was in second place because of starting to play competitive spelling bee, as it was seen in episode 14.
Rachel is childhood friends with Maya since they live near each other. Ever since they were children, Rachel has been taking on the responsibility of looking after the troublemaker Maya, sometimes being taken advantage of. Despite that, she also was always protected by Maya which makes Rachel trust her. She strives to lead a quiet school life but is often dragged into various things by Maya.
Rachel is Maya's best friend and they have known each other since elementary school. She always tries to stop Maya from overdoing things but cannot seem to do so. Her mother works late at a local hospital and her father travels the world as an Photographer. Rachel finds out about the Glitter Force warriors when Maya decides to tell her because it is hard for her to keep a secret from her best friend. She later runs into the mysterious merchant who gives her a Glitter Charm that she later decides to use to help her friend as Glitter Diamond.
Maya Aida: Maya is one of Rachel's very close childhood friends and current schoolmate.
Clara Yotsuba: Clara is another one of Rachel's childhood friends; they met in elementary school.
Mackenzie Mack: Mackenzie is one of her teammates. Rachel used to be jealous of Mackenzie spending time with Maya, but eventually moves on from her jealousy, and the two end up good friends.
Rory: Rory is Rachel's transformation partner who helps her transform into Glitter Diamond.
Natalie: She and other Glitter Force warriors met her during the battle with Regina.
Glitter Diamond is Rikka's Pretty Cure alter ego. She represents wisdom.
Rory cries out his name before Rachel first places her transformation Glitter Charm onto Rory's silver heart medallion object and shouts "Glitter Force Makeover!". She then spells "L-O-V-E" on her Glitter Pad and the transformation begins. She is seen floating around with her body, except for her head, glowing with blue light. First, her hair glows blue and grows into a long ponytail. Her hair then turns to a lighter blue and her hair accessories and diamond shaped earrings start to appear. Her dress then appears and her Glitter Force attaches itself to it. Next is her heart brooch, bracelets and boots. Finally, her dress ribbon appears on her pelvis and Glitter Diamond poses saying her introduction speech.
Twinkle Diamond - is Glitter Diamond's main attack, with the incantation "Activate Glitter Pad! Sparkle! Now, shine! Twinkle Diamond!". Doki Doki Pretty Cure!, the incantation is instead "Sparkle! Twinkle Diamond!" Glitter Diamond activates her attack with the Glitter Pad. It then blinks twice and she points her finger towards the foe, releasing a flurry of blue diamond-shaped energy beams. With this attack, she can also freeze enemies.
Diamond Shower - is Glitter Diamond secondary individual attack that appears in episode 9 of the first season, firstly, she summons the Glitter Heart Arrow and sets the Glitter Charm within the middle of the heart, then it shines, she takes the arrow and she taps her arrow a couple of times releasing, a big wave a diamonds.
Like her Glitter Force partners, she can use Power-Ups when she takes it seriously in the battle. When this happens, a blue light appears around her body.
Rachel comes from the Hebrew word meaning "ewe" or "one with purity".
Her Japanese last name, Hishikawa (菱川): Hishi (菱) means "a diamond shape", while kawa (川) means "river".
Her Japanese name, Rikka (六花): The kanji Rikka (六花) means "snow". Individually, Ri (六) means "six" while ka (花) means "flower".
- In the Japanese version, it is revealed that Rachel's birthday is on September 17th, making her a virgo.
- Main page: Rachel/Gallery