Run Elsie Jewelria

Run Elsie Jewelria is a childhood friend of Lala and the girl version of Ren Elise Jewelria. As Run and Ren are royalty from planet Memorze, they can change gender in mind and body upon triggering a specific stimulus; in their case, a sneeze. Ren hates Rito, especially after he accidentally kissed him, but Run fell in love with Rito because of that kiss, which caused Ren to further dislike Rito.

Run becomes a famous idol and actress and released several albums. She becomes friends with Kyouko after Run played an antagonist in her show, and now they are often seen together, even releasing a few albums together.

In To-Love-Ru Darkness  Chapter 9 or To Love-Ru Darkness Episode 6, Run and Ren permanently separated into two separate beings after reaching 'adulthood'.

Appearance
Run has   hot pink eyes  and  has  long light green hair with two points sticking out at the top. Her body appears slender and curvy, she is always wearing clothing typical of Idols in Japan, especially her Blue Metalia outfit that she wears when starring at the Magical Kyouko show.

Personality
Her personality can be described as determined and obsessive (especially where Rito is concerned). On some occasions, when it comes to Rito who she loves so much, she can be quite cheery and sweet, and would often cling on to him, Run can also be a bit of a stalker to him. She can get a little mad when it comes to Lala and her relationship with Rito. Run can be a bit melodramatic and can misinterpret things easily, more so in the anime, a good example of this in episode 16 of the original series.

In the first series, her personality was really childish, and she would always try to pull pranks on Lala (which ultimately fail) to get back at her for all of the mischief she suffered from her. But in To-Love-Ru Darkness, she has greatly matured, as she no longer pulls any pranks on Lala and focuses on her work as an idol. She tries harder to gain Rito's love. Especially now since she is now a full woman and is no longer with Ren.

Childhood
Sometimes Run would be taken to Deviluke to play with Lala. Apparently she really hated being part of Lala's experiments and being forced to go through so much trouble (even while Ren was in control). Even though Run hated Lala, her male counterpart Ren falls in love with her.

Powers and Abilities
It is said that due to evolution, those from Memorze like Run are born with both male and female genders, each with its own personality. Normally Memorzorians would change monthly, but due to the differences in environment and magnetic fields on Earth, Run and Ren would change from a sneeze. When Run is in control, she is able to communicate with Ren within her subconscious (this works for Ren as well). After reaching adulthood, they both physically separate, and Run no longer shares a body with Ren, so this ability is not usable. Ever since the separation Run has tried harder to harbor Rito's love.

Run is shown (comically) to have great speed and strength, like running really fast while carrying a huge hammer, but cannot control her speed while carrying it.

She would often order certain items from the galactic internet to try and humiliate Lala.

Lala Satalin Deviluke
Run and Lala have been more or less friends since childhood. But unlike Ren, who loved Lala despite being treated similarly, Run holds a grudge against Lala for all the torment she made her go through, and spent several chapters trying to get revenge on Lala through various outrageous schemes and pranks, such as using the youth skunk and the clothes-destroying bomb. All of her attempts for revenge fail, and Lala is completely clueless of Run's feelings or her attempts at getting revenge. There are times when Run has a more friendly (or at least a more civil) relationship Lala.

Run considers herself to be Lala's rival in love, as she is also in love with Rito.

All of her childish and outrageous schemes to humiliate, harass, or get back at Lala end in failure, but overtime, her attempts become less frequent, perhaps due to skipping school often to work as an idol. She has since become more level-headed and mature.

Ren Elise Jewelria
Ren is Run's male counterpart, who's shared the same body with her since birth, until they reached "adulthood", and the two to permanently split bodies. Run hates Lala but Ren is deeply in love with her. It was through Ren that she experienced the kiss he accidentally had with Rito, the cause of her love for Rito. Run hates it when Ren picks a fight with Rito over Lala, even calling him pitiful.

It was seen that Ren and Run are capable of communicating with each other while sharing a single body. They generally took turns with who lived in the shared body, while the other slept. Run eventually became the more prominent personality, and she would sometimes turn back into Ren in situations that are very undesirable for him, sometimes intentionally when the situation is undesirable for her.

After they became separate people, they began living together. It's not known in detail what their lives are like together, or how they get along. Ren has shown a slight care for Run, like when he advices Rito to not hurt her or any other girl.

Rito Yuuki
Run has been in love with Rito since Rito and "Ren" accidentally kissed each other. Since then, she has tried her best to win him over Lala and make her look bad in front of him, although many of her attempts would often get Rito into trouble or erotic situations. Rito was sort of aware that Run likes him but never even consider it.

In To-Love-ru Darkness,  Run is now a famous idol. She has also greatly matured around Rito and becomes closer to him on their date. During their date, Rito realizes that he hardly knows much about her. From this date Rito is now aware of  how deep Run's feelings are towards him, but she is saddened with the fact that Rito would never see her as a real girl while sharing the same body with Ren. This was the case until Run and Ren reached "adulthood", causing them to split mind and body. Since then, Run is determined to try harder to gain Rito's affections.

Rito has begun to show more sympathy towards her feelings, going as far as considering her as a lover for the harem plan, but quickly shakes it off.

Kyouko Kirisaki
Run first met Kyouko when she starred as a villain in her show. At first, Run didn't take too kindly to Kyouko but after getting to know her better, Run sees that Kyouko is a really kind person who listens to Run's music and even reads her blog  (and finding out that Kyouko is human/alien hybrid), and they became good friends. Kyouko knows about Run's feelings towards Rito and wishes the best of luck in getting him.

In To-Love-ru Darkness, Kyouko visits Sainan High and asked Rito to be her tour guide, intending to find out more about Rito for Run. When Rito saved her from a swarm of rampaging fans, Kyouko began to also develop feelings for him, something she has yet to tell Run.

Trivia
Run appeared at a television show (probably the show where she co-stars with Kyouko) in Mayoi Neko Overrun Chapter 6.