Magnetic Personality of the Lion Clan
The Lion Clan is not a stranger to the village, and has been part of the village since the founding.  Matriarchal in their internal heiarchy, they are known for strong women and strong will.  If something absolute, positively must be done no matter how long it takes, the Lion Clan is the go-to clan.

The Clan is not, however, known for being incredibly sociable, and Hikaru breaks the stereotype with a nuclear bomb.  While the Raioneiki tend to believe family ties end outside of the clan, Hikaru has taken to the philosophy that the entire village is her family, and is known by virtually the entire Village of the Hidden Jungle.

Lion Clan Philosophy
Members of the Raioneiki clan are generally part of very tight knit families led by their mother/wife, who then follows the chain up the generations, with one woman being seen as the heart and head of the clan itself, with other clan members being seen as family as well, but not as important as immediate family.

Courage, passion, and willpower are the most valued traits within the clan, and to give up is seen as simply allowing oneself to fail.  With enough determination, anything is possible - even miracles.

The Girl Hikaru wants to be

Above all else, Hikaru wants to be someone who makes her family proud, whatever path she might take.  Currently, her path is that of a kunoichi who desires to be the best she can be, and who will accept nothing but her full effort.  While already on her desired path, Hikaru wishes to grow up be someone others can depend upon, no matter their troubles, and who helps others achieve their full potential.  She cannot stand seeing someone wasting their potential, and the greater the potential, the more it upsets her.

Finally, while she will never bring it up herself (but will happily admit to it), Hikaru wishes to be a good mother, just like Yuriko, her own mother, and to have a wonderful husband, just like her mother has her father, Keiichi, whom love and trust one another unconditionally.

Relationships
Kariko Kimokinaya
Hikaru thinks of Kariko as her closest friend, always apsiring to drive her friend to reach her amazing potential as a kunoichi while very subtly attempting to guide her away from the impassable cliff that is playing the biwa (although she is unable to tell Kariko directly that the playing is bad, often saying things like "It's much better than last time" and "You're definitely improving!").  She feels that she can talk with Kariko about anything with open honesty (except, it seems, playing the biwa and Kariko's cooking), and wants them to grow strong together.

Hikaru's Kekkai Genkai
Magnetic Bonds
Appearing in only Hikaru and surprising her family entirely, Hikaru has the strange ability to manipulate the magnetic forces around her, allowing limited manipulation of metal tools, weapons, and objects, as well as letting her sense the magnetic fields generated by other things, including the planet.

This Kekkai Genkai is akin to the manipulation of an element not within the basic five, such as Wood, Ice, Bone, and Dust.  While not quite a full-on manipulation of metal, it has the potential to manipulate other things also affected by magnetic fields, however subtly the influence may be.

Known Jutsu and Techniques

Ten Strikes, Snake Sword
  Hikaru separates the segments of her sword and whips the blade around a target before guiding it to attack from several angles at once, then pulling the segments back into a sword once more.

Family, Friends and Enemies

Yuriko Raioneiki
Hikaru's mother, born into the Kametetsugaku/Turtle clan, is a loving, open person who is incredibly easy to read.  Gentle almost to a fault, she is the first person to welcome a guest and start up the tea, and truly loves meeting people, new and old.  She has something of an eidedic memory when it comes to names, faces, voices, and other aspects of people, with a near instant recall of events, histories, gossip, and stories told by and about others and herself.  While she is not a ninja, she has the uncanny ability to appear without being noticed, usually with a smile, something tasty to eat... and a story about her daughter.

Not as embarrassing to her children as her husband (whom she refers to as 'Kei-Darling' without a hint of embarrassment or sarcasm), she can still sometimes tell a story or anecdote about her children that makes them feel awkward and embarrassed around company (which is usually offset by delicious treats).  She refers to Hikaru as "Hicchan".

Keiichi Raioneiki
Her father, a talented Jounin, would be someone you would never expect to be a competent ninja by how he acts at home.  Professionally, he is an able leader, talented user of lightning and wind ninjutsu, incredibly clever and strategic, and incredibly dependable.  At home, however, he is someone else entirely.  To him, Hikaru is Daddy's Little Princess, who must be doted upon, loved, and agonized over every moment.  While Yuriko usually manages to reign him in, she is not always able to prevent "Otou-chan" from focusing his paternal affection a bit too much on Hikaru.

He lovingly refers to Yuriko as Yu-tan, and still acts like a newlywed around her, regardless of company (although he can behave while on duty and when it really matters).  He refers to Hikaru as 'My Lovely Daughter Hikaru', even in casual conversation, and carries photos of her everywhere to show others.  He's a bit like Maes Hughes that way.

Mikoto and Makoto Raioneiki
Her older twin siblings by five years, Mikoto (Elder twin sister) and Makoto (Younger twin brother).  They are promising ninja in their own right, and work amazingly well together, even performing spontaneous team maneuvers without any prior planning, with Mikoto focusing more on taijutsu and Makoto on ninjutsu, as usual for the Raioneiki clan.

They refer to Hikaru by her name without a suffix, and she calls them "Mikoto-onee-sama" and "Makoto-onii-sama", respectively.

Tropes used to define Inazuma Raioneiki
Amazingly Embarrassing Parents: http://tvtropes.org/pmwiki/pmwiki.php/Main/AmazinglyEmbarrassingParents
Bokukko: http://tvtropes.org/pmwiki/pmwiki.php/Main/Bokukko
Even The Girls Want Her: http://tvtropes.org/pmwiki/pmwiki.php/Main/EvenTheGirlsWantHer
Meaningful Name: http://tvtropes.org/pmwiki/pmwiki.php/Main/MeaningfulName
Whip Sword: http://tvtropes.org/pmwiki/pmwiki.php/Main/WhipSword