Minazuki Karen

A third-year student at L'École des Cinq Lumières Middle School, and the last Cure to join the group in Yes! Pretty Cure 5. Because of her parents' job, she has been raised by the mansion's butler. At school, she is the student council president, and is very popular by the juniors together with her fellow student council member and best friend, Komachi Akimoto, for her cool and inspiring demeanor. Her alter ego is the Cure of Intelligence, Cure Aqua (キュアアクア).

Yes! Pretty Cure 5
As a child, Karen always missed her parents when they were away, even though she pretended not to. When she was older, she met Akimoto Komachi, and they became friends while working on a project together.

One day after school, Karen was in the school library with Komachi when they were interrupted by Yumehara Nozomi. Nozomi insisted that someone had entered the library without either of them noticing, which was clearly impossible. A few minutes after she wandered off to look for her imaginary friend, Karen and Komachi heard strange noises. Investigating, they found damage to the floor and shelves in one part of the library, with no obvious origin. Stranger still, the damage mysteriously repaired itself when they left briefly. From this point on, Karen and Komachi tried to talk to Nozomi in order to find out what had happened, as the junior was most likely involved.

During these investigations, Karen realized that Nozomi and her best friend, Natsuki Rin, had become friends with the new student Urara Kasugano, even though they had nothing in common. Komachi became involved as well after the three girls told them some ridiculous story about "Pretty Cure". Despite her best efforts, the four invited themselves over to Karen's house to try to convince her of their story. However, in the middle of an unconvincing explanation involving Coco, a living fluffy animal, the girls were suddenly attacked by Bunbee, who stole another strange creature and turned Karen's gazebo into a monster. Karen ran and hid, but it became clear that the others did not stand a chance unless she was able to transform herself. A blue butterfly flew out and landed on her wrist, but immediately disappeared, leaving Karen to watch helplessly as Bunbee escaped with the Pinky he had captured. Karen admitted that Nozomi and the others had been telling the truth, but said she could not help them.

Nozomi, however, was incredibly stubborn and annoying about it, and just would not get the message, even getting Jiiya to tell her things for some reason. Frustrated, Karen stormed off, but Nozomi followed, and told Karen that what they had in common was their love for their parents. Karen was shocked by the idea that Nozomi actually understood her, and agreed that, Pretty Cure aside, they could be friends. Then Bunbee attacked again, and turned the Pinky from before into a Kowaina. Things went badly once more, but Karen was determined to help the others, and declared as much. The blue butterfly returned, this time giving Karen the ability to transform, and under her directions the girls saved the Pinky and defeated Bunbee.

Once gathered, the five Cures were able to rescue Coco's friend, Nuts, from the Dream Collet. Nuts raised the question of who was the leader of Pretty Cure, and while Nozomi suggested Karen, Karen hastily turned down the position and nominated Nozomi herself, a suggestion immediately supported by the others. After Nuts started living in a small storehouse that Karen was certain was too small for the purpose, Karen brought a housewarming gift; a small pot of blue Chinese bellflowers from her greenhouse. This, however, led into a conflict with Rin, who was also bringing in a pot of bright red tulips. Eventually, by being forced to fight Arachnea together, they learned to get better along.

Karen, the serious student council president, almost immediately began to get in the way of the more free-spirited Nozomi's ideas. First she shot down Nozomi's plan to advertise Nuts's accessories by bringing them to school, pointing out that this was against school rules. . Not much later, understandably unimpressed by Nozomi's poor grades and study habits, she tried to force the Pretty Cure leader to study, but eventually relented in favor of setting more gradual goals. There were apparently no hard feelings, however, as Nozomi and the others were more than willing to help Karen solve the various student organization's budget problems when the chairwoman refused to give them any more money.

As Cure Aqua, meanwhile, Karen made a habit of rescuing Masuko Mika when she was in danger. Mika, meanwhile, interviewed Karen for the Cinq Lumieres News, with unflattering results.

When a new creature from Palmier Kingdom, Milk, comes into the picture, Nozomi accidentally destroyed the butterfly decoration the others had been working on, and Karen joined Rin in lambasting her about her carelessness, calling Komachi wishy-washy over her attempt to not take sides. She immediately tried to take back her words, but they continued to bother Komachi until the following afternoon, when Karen's attempt at an apology was interrupted by an attack by an insane powered-up Girinma. Cure Aqua and Cure Mint were defeated almost immediately, then caught by Kawarino. Cure Aqua was forced into a nightmare in which an illusion of herself as Karen lectured her about her tendency to remain distant from others, resulting in her lacking close friends and, ultimately, being alone. Cure Aqua was thus easily placed under the control of a Mask of Despair. The controlled Cure Aqua completely ignored Nozomi's attempts to remove the mask, and helped to restrain her after she transformed into Cure Dream. Along with the other Cures, Cure Aqua was eventually restored to her normal self by Cure Dream's efforts at reaching out to them.

Personality
Karen is often seen as inspiring to other students due to her calm and stoic nature. This, however is her outer character, she can actually be very lonely when thinking about her parents, whom she secretly misses. Because she has known Komachi for such a long time, Karen often feels the responsibility to be there for her, but this feeling is inside her for everybody, something she thinks comes from being the president of the student council. Because of her position, Karen is able to memorize all the names and faces of all the Cinq Lumières students, and also easily takes responsibility when something happens to the school, as seen in the second episode where she wants Nozomi to explain what happened to the library the other day.

Cure Aqua
"The blue spring of intelligence, Cure Aqua!" 知性の青き泉、キュアアクア！ "Chisei no aoki izumi, Kyua Akua!" Cure Aqua (キュアアクア) is the last to join the group, and her costume has a design resembling that of Cure Mint, her counterpart. Cure Aqua's biggest difference from Karen is that she is more loyal to her team and has a much stronger and gentler personality, and her voice changes slightly as well to a more stronger one. She is usually the one to help the others. She, as Nozomi learns, is the most trustworthy Cure. In the beginning, Karen is reluctant to join Pretty Cure, but in sixth episode, as the girls are being manhandled, Karen stands up to her friends, vowing to protect them regardless of transformation. The butterfly that eluded her previously reappears and successfully lands on her wrist, enabling her to transform to the Pretty Cure of Intelligence.

Alone, Cure Aqua can perform the attack Aqua Stream. When her powers get upgraded with the Aqua Ribbon, she uses Aqua Tornado. At the end of the first season, all the five girls can combine their powers and do the attack Five Explosion.

In the next season, Aqua is able to use the attack Sapphire Arrow. With the other five girls and their Cure Fleurets, she can perform Rainbow Rose Explosion and, with Milky Rose at the end of the season, Floral Explosion.

Relationships
Her parents are musicians and often go on tour, and as such Karen has been mostly raised by her butler. She misses her mother and father, but will not ask for them to come home for fear of disturbing their work, so despite wealth and popularity, she is often lonely when not around with her best friend, Akimoto Komachi. Komachi is her best friend and a fellow student council member, and they are inseparable at school. Seen around school as cool and inspiring, most of the students look up to her, though this does not interest her much.

Etymology
Cure Aqua is supposed to be directed toward her power over water, as "aqua" is Latin for "water".

Trivia

 * Karen occasionally shows an exaggerated fondness for grape juice.
 * Karen has a number of similarities to Yukishiro Honoka from Futari wa Pretty Cure, most notably their nearly identical backgrounds and their reputations for being highly intelligent and polite. As such, her relationship with Natsuki Run is interesting in how much it differs from Honoka's relationship with Misumi Nagisa.
 * The theory behind their awkward relationship is that their Cure selves, Cure Aqua and Cure Rouge, represent water and fire respectively. In many cases, these two elements are seen with an antagonistic, or opposite, relationship.
 * Karen has also been compared to Zakuro Fijiwara, from the older magical girl series Tokyo Mew Mew; both of them are the oldest and most serious of the group, very stoic compared to the others, and were the last to join the group after two episodes. While this may seem like a less obvious connection, it is difficult to deny that Tokyo Mew Mew was an influence on Yes! Pretty Cure 5.
 * Episodes focusing on Karen seem to disproportionately concentrate on showing her relationships with her female teammates becoming increasingly close. Karen's relationship with Milk is implied to be analogous to those between Nozomi and Coco, Komachi and Nuts, and Urara and Syrup. Karen is never seen expressing romantic interest in a male character, except when others are doing the same . A recurring theme with Karen involves her being reluctant to express her true feelings, especially to her parents.
 * She may look similar to Cornelia Hale from W.I.T.C.H. because of her long hair, rich family, stoic and serious personality, as well as the disbelief of magic. It should be noted, however, that while Karen is blue-haired and controls water as Cure Aqua, Cornelia is blond and controls earth, which is the element of Karen's best friend.