Tsukikage Yuri

Tsukikage Yuri is a third Cure in Heartcatch Pretty Cure!, though not much is known about her. She appears in the dreams of Hanasaki Tsubomi and Kurumi Erika. In the series, she is the first Cure to make an appearance, her identity being Cure Moonlight (キュアムーンライト).

Prologue
Cure Moonlight is seen in the prologue of the series, where she fights against Dark Pretty Cure before the Great Tree of Hearts. Realizing that she will not win the fight, she uses the last of her power to protect the withering Tree and the two fairies Chypre and Coffret, telling them to go and find a replacement for her. Just as they run, her Pretty Cure Seed breaks, and she is hit with Dark Pretty Cure's attack.

Aftermath
Although Cure Moonlight has not been seen since then, the events that occured before the Tree of Hearts occasionally appear in Tsubomi's dreams, the same day she becomes a part of Pretty Cure. It is also confirmed that Tsubomi's grandmother, Hanasaki Kaoruko, knows Cure Moonlight, but most likely does not know her whereabouts and condition.

Although not killed, Yuri's Pretty Cure Seed is destroyed, taking away her ability to transform into Cure Moonlight. However, she keeps a part of the Pretty Cure Seed as a charm while she lives a normal life as Kurumi Momoka's classmate. At the school, it is revealed that Yuri often takes notes from class for Momoka, who often works when school starts, and they are both at first name-basis.

She seems aware that Tsubomi and Erika are the new Pretty Cure, as she gives them advice about friendship and courage while visiting the botanical garden that Kaoruko directs. When Dark Pretty Cure summons her Dark Tact to finish Pretty Cure, Yuri appears behind the girls so that only she can see her. Yuri seems to give her an unspoken request, which Dark Pretty Cure accepts, thereby leaving. Tsubomi and Erika wonder why she left, not seeing Yuri as she leaves, looking at her broken Pretty Cure Seed.

Cure Moonlight
Gekkou ni saeru ichirin no hana, Cure Moonlight! Cure Moonlight (キュアムーンライト) is the Cure that Yuri transforms into. As the sole protector of the Tree of Hearts in the early past, Cure Moonlight is capable of fighting with martial arts and use the attack Floral Power Fortissimo, which Cure Blossom and Cure Marine can only do together, and also use it for further use than purification. She is capable to fight evenly against Dark Pretty Cure, who is considered Sabaku's right hand.

When Cure Moonlight's Pretty Cure Seed is destroyed, it is likely that she lost her powers to transform and fight, though it is not confirmed.

Relationships
Sabaku: While they are viewed as enemies in the season's prologue, the opening sets Cure Moonlight and Sabaku together, hinting of a special relationship between them. This relationship is not revealed to be more than that of nemesity.

Dark Pretty Cure: Yuri's relationship with Dark Pretty Cure seems to be the antagonistic sort. However, just when Cure Moonlight's Pretty Cure Seed is destroyed, Dark Pretty Cure gets a shocked expression, hinting a deeper relationship between the two of them.

Kurumi Momoka: Although they are on first-name basis and Yuri often gives Momoka notes from classes she is absent from, they do not seem that close.

Etymology
Tsukikage (月影): Tsuki (月) translates to month; moon, a reference to her alter ego as Cure Moonlight. Kage (影) translates to shadow.

Yuri (ゆり): A name that has a vast variety of meanings depending on how it is written in kanji, and since Yuri's name is written in hiragana instead, it is impossible to find an exact meaning for it. The most common meaning is lily (百合), which would fit with the theme of Heartcatch Pretty Cure!.

Cure Moonlight: Despite the theme of Heartcatch Pretty Cure! being flowers, moonlight is the light that comes to Earth from the moon.

Trivia

 * Being 17 year old, Cure Moonlight would be the oldest on-going Cure in the franchise, had her Pretty Cure Seed not been destroyed. She is also the second oldest Cure, losing only to former Cure Flower.
 * It is speculated by fans that Cure Moonlight's name comes from the fact that the moon manipulates the sea, which Cure Marine has the power of, in the case that Cure Sunshine has the name of the sun which keeps life in flowers, which Cure Blossom controls.