Lala Satalin Deviluke

Lala Satalin Deviluke is the main female protagonist of the story. The story begins with Lala running away from home as she didn't want to get married to any of her suitors. Due to an accident, she ends up naked in Rito Yuuki's bathtub. Upon arriving on Earth, Lala pretends to love Rito to keep herself from getting married, but really does fall in love with him after she misinterprets a statement that Rito shouts in self-defence. Lala's second name (Satalin) might be a reference to Satan. This pattern can be seen in her sisters' and father's names, too. However it is most certainly just a play on their family name and devilish tails/wings.

Appearance
Lala is a highly attractive teenage girl with long bubble gum pink hair, emerald green eyes, curvaceous and often referred to as perfect figure. According to Ringo Yuuki Lala's measurements are B89, W57, H87. Her most distinguishing feature is her tail which extends down from the base of her back. Her tail is long, thin, and ends with a heart-shaped tip. Ryoko Mikado referred to her in chapter 30 as "Devilukean" in a manner which suggested it was the name of her species. At the beginning of the series she is almost always seen in her costume robot, Peke, in what can only be called an enlarged version of Peke himself (see above). Wanting to fit in more with the people of earth, she now has Peke dress her in various earth clothing styles; she has also bought herself a large number of earth clothes for use when Peke is out of energy.

Personality
She is incredibly enthusiastic about the smallest things and has a very bubbly and slightly child-like nature, which is most likely the result of being raised as the first princess of Deviluke. Judging from appearance alone, she can be considered a little air-headed. However, she is known for her genius-level intellect as seen in her amazing array of inventions; her planet even wanted to use her for weapons research. She is very caring and generous and appears to have a need to make everyone she cares about happy. She is very naive about earth culture and will often make highly dangerous mistakes.

Despite her naturally cheerful and somewhat childish nature, Lala is not as emotionally immature as she would appear. She has, on rare occasions, become upset and angry at other characters even Rito over serious issues. One incident in particular involved her spending the night with Haruna because Rito had yelled at her, which made her doubt if her affections would ever be reciprocated. One great demonstration of her emotional maturity was when during the Trouble Quest incident, her sisters tried to force Rito to admit his feelings for her but upon seeing the stress he was under stopped them after having already found out that he does like her in some way.

She has also shown an amazing level of compassion for other characters. One example of this is when Haruna admitted to her that she is also in love with Rito, Lala not only moved out of his cupboard in favour of a joint house in the roof but also stopped throwing herself at Rito to hug him in order to be fair to Haruna and make it easier for her. Another example is when her and her sisters were younger, When her sisters fought, Lala would often led her inventions run around so that they would settle their differences and work together, even though it would result in Lala getting lectured by Zastin.

On occasion, Lala will say something ironic in relation to her own decisions. For instance, telling Saki not to run away from home, or telling Momo not to sneak into someone's bed when they are sleeping.

Due to never really being alone her entire life, she has no notion of modesty and is more than happy to walk around naked (much to Rito’s disdain) but has in more recent times gotten better at knowing where and when not to be naked, though she still makes a habit of walking out of the bath room naked when she needs something. It can be pointed out that although Lala holds no real issue with appearing naked around people, more so in recent times, she is in no way perverted or in any way interpreting the action as sexual. She actually is for one very bashful when it comes to being touched or viewed in a sexual way or from any overly compromising angle. Rito found out about this after she landed on top of him when they were on their way to save Celine and was for once incredibly embarrassed about this. However, while she has no sexual intentions, Lala seems to take some amusement from making Rito blush and panic, a sight which she has declared 'cute' more than once.

In To Love Ru: Darkness, Lala has seemed to mature slightly, though she still will walk around the house naked at times and continue her other usual tendencies. Lala and Rito seem to have a much better friendship, especially due to the fact that Rito confessed his love to her. However she also constantly tries to push Rito into confessing to Haruna as well, so the three of them may get married. As the series progresses Rito realized that it is bad of him to treat Lala as if she's insurance to his love with Haruna, and even starts to consider Lala's offer of marrying both of them.

Childhood
As the first daughter of King Gid of Deviluke and her unnamed and unseen mother, Lala was born the first princess of the planet Deviluke. She has two known siblings, the twins Nana and Momo, whom she is very close to. As a child she was friends with the Memorze royal Run/Ren, though she seemed to prefer Run who she used to unknowingly torment. She is known to have a rather pleasant relationship with her father as she warmly recalled to Rito of a time that she was lost in the forests of Deviluke and how her father found her and took her back to the palace on his back. It was not long after then that she built Peke the costume robot which allowed her to fly and gave her a permanent friend to always be with. As the first princess and presumed eventual successor to the throne of Deviluke, it appears that she must marry so that both she and her spouse can rule together. As such she was continuously presented with male suitors, all of whom she has turned down. When she finally couldn’t take it any longer, she escaped from her home to earth so that she could have some freedom.

Powers and Abilities
Being an alien, Lala has far more strength, power and speed than the average human. Her physical strength (without any inventions or powers) surpasses any human on Earth, and maybe even some aliens in the solar system.

Her weakness is her tail. On Planet Deviluke, females' tails are far more sensitive than males'. When someone touches Lala's tail, she becomes weak and seems to lose her strength, though she can shake anyone off of her tail with her astonishing strength.

Lala's main method of combat (and sometimes life) are her many inventions. She is considered a genius and has made many inventions. However, a running gag in the plot is that her inventions usually do not work as well as Lala and the others had hoped. A list of some of her inventions and their functions are as follows:
 * Pyon-Pyon Warp-kun: This invention allows any living person (or "unit", as used by Lala) to warp a short distance to a random destination, as you cannot specify the destination. Lala explained that it was only used in emergency situations. After the ring is used once, it will take a whole day for it to recharge its energy for another time's use. Another setback is that Warp-kun can only warp the person, not their clothing, meaning that when the person warps to a random place, they will be completely naked. However the DX version has been modified so it can transport people and clothing but unfortunately when it teleports someone, the machine itself stays at the place of the original teleportation.
 * Go-Go Vacuum-kun: This invention works exactly like a vacuum; it sucks things up inside it. However, the power of this vacuum is so great that it has the potential to suck up anything in its path.
 * Sniff Sniff Trace-kun: A robotic dog that can sniff out anything with a trace. However, he has a tendency to wander off if he smells another thing that has a nice scent.
 * Slosh Slosh Warp-kun: A toilet-like machine that warps a creature to another planet by "flushing" them down the machine. It seems to work just like Pyon Pyon Warp-kun, as it transports a living thing to a random place, but the creature still has their clothing and it does not need a whole day to recharge.
 * Change Boy Girl-Kun: A gun-like machine that can change a boy into a girl, hence the name. Unfortunately it has a time limit so it can be embarrassing when a girl changes back into a boy in public.
 * Maru Maru Change-Kun: A Machine that switches the bodies of two people. This invention has only been used three times in the manga; the first was when Lala switched Rito and a stray dog; then Lala switched bodies with Haruna; lastly Yami and Mikan switched bodies for a day.

Relationships with Other Characters
Lala has experienced many friendships in the story, some stronger than others. Aside from her family and royal bodyguards, here are her connections to her peers.

Rito Yuuki
In the first chapter, Lala only pretends to love Rito so that she can stay on Earth and escape her marriage suitors. However, after he saves her (or in actual fact tries to save her) from Zastin, she states that she really does love Rito and wants to marry him. Throughout the story, she openly shows her affection to him, even going so far as to walk around his house naked, hoping that she will win his affection.

When Haruna tells Lala that she also loves Rito, her showing of affection towards Rito stops for a while, but then she decides to support her own love and goes back to openly showing her affections for him.

As the story progresses, her love for Rito seems to have matured even more as it is not as insane as before. Her (somewhat) calmer attitude around him has allowed them to develop a closer relationship. A clear example of her maturing love is her acceptance that Haruna, her best friend, also loves him and that she would fight for him but be happy for her if he chose Haruna instead.

It was not until the last chapter that Rito finally confessed to Lala that he loves her. She was also overjoyed when she heard that he loves Haruna as well.

Haruna Sairenji
Lala regards Haruna as her best friend and will often go to her for advice when she is not sure about some part of Earth culture or Rito. Later, Haruna reveals to Lala that she too is in love with Rito. This causes Lala much guilt over how she has acted around Rito over the previous year; she even tries to distance herself from him in an effort to make Haruna feel more comfortable.

Later after much thinking she confronts Haruna and declares herself her official love rival. She has since reverted back to her over-the-top method of displaying her affections.

Mikan Yuuki
Lala thinks very highly of Mikan, mostly because she lets her stay in her and Rito's house and Lala loves her cooking.

Lala and Mikan are very good friends and Lala always tries to help her with chores (even though she messes up the chores most of the time).

Golden Darkness (Yami)
Lala considers herself a friend to Yami, going so far as to help her pick out new clothes (Chapter 61), and help Yami realize how nice Rito really is by letting Mikan and Yami switch bodies for a while (Chapter 139).

Yui Kotegawa
In many ways Lala and Yui are each others' opposites; in appearance and personality respectively, Lala is pale skinned and colourful while Yui is tanned in complexion and has a darker image. They are friends even though Yui does hold some resentment over Lala's lack of decent behaviour and to a certain extent jealousy over her closeness to Rito whom she is also in love with.

Lala likes Yui a lot and often tries to find ways to include her in things that they are doing. While others have a tendency to view Yui in a formal and in many cases resentful light, Lala does not. However, due to Lala's nature it is doubtful as to whether she would view anything as bad.

Whenever a comparison of girls' figures is brought up, Yui and Lala tend to come into the picture as examples of what other girls wish to achieve as the two are considered to have the best bodies. It can be viewed as ironic that even though these two have the best bodies they are the only two so far seen who pay no attention to their outer appearances.

Saki Tenjouin
While Lala tries to be friends with everyone, a girl named Saki Tenjouin holds a grudge against Lala. Saki used to be the most popular and beautiful girl in school, until Lala showed up and attracted all the attention away. Saki goes so far as to go naked, set up booby traps, and even shoot Lala with mustard to try to humiliate her. Most of her antics usually backfire. Lala is mostly oblivious to the fact that Saki really doesn't like her, and is still friendly to her.

Ren/Run Elise Jewelria
Ren

When they were children, Lala would often dress up Ren as a girl and call him a cry baby. Lala would also perform disastrous experiments on him and test out her inventions on him. Despite this, Ren is in love with Lala. One day, when Ren asked Lala if she would marry him, she replied she would if he could become manly. Upon arriving on Earth, Ren, who has grown up a little, desperately tries to prove to Lala that he has become manly by trying to one-up Rito. However, Lala doesn't really care about Ren's feelings as she only wants Rito.

Run

While Ren is deeply in love with Lala, Run is one of the few people who despise her. She never forgave Lala for tormenting her as a child and holds a deep grudge against her. To make things worse, Lala has Rito, whom she is in love with. She, much like Saki, goes to outrageous extremes to try to humiliate Lala but they usually backfire as well.

Mikado Ryouko
"Mikado-sensei", as the kids usually call her, is the high school's nurse and one of Rito's and Lala's personal friends. When Lala had her strange flu, it was revealed that she is in fact also an alien and provides exotic herbs and treatment methods intended for other aliens that live unbeknownst amongst Earth inhabitants.

Usually, she is very sexily and/or scantily-dressed. Her behaviour doesn't leave much room for speculation whether she is kinky and/or perverted herself, as she, for instance, openly teases her young patients (like Rito) sexually, even going so far as to provide the girls with "special medicine" or advice on how to seduce him behind his back. She is very well-built and has by far the largest bust of the entire female cast.

Kenichi Saruyama
Lala and Saruyama are not seen together too often. They are friends, but Lala is totally oblivious to the lust Saruyama has for her. Lala knows that Saruyama likes Riko (Rito as a girl) and even helps him out by turning Rito back into a girl and making him/her go on a date with Saruyama