HikaHaru

HikaHaru is the Het ship between Hikaru Hitachiin and Haruhi Fujioka from the Ouran Highschool Host Club fandom.

Canon
Ep 16 - Operation Haruhi and Hikaru's First Date!

Because of his immaturity in dealing with others, Hikaru is childishly over-possessive of each club member. An example of this occurs during wherein Hikaru becomes jealous of Haruhi's childhood friend, Arai. Haruhi slaps him when he becomes rude, and he runs away with Kaoru chasing after. Another example of this is in the manga, when Hikaru becomes annoyed at Haruhi's constant chatter about Tamaki and his family situation. He storms off yet again, with Kaoru following once more. In the end, it is Kaoru who helps Hikaru understand his romantic feelings for Haruhi despite his own.

Despite Hikaru and Kaoru's efforts to remain a single entity, it is Haruhi who manages to decipher which twin is which without resorting to guesses, as she sees them as two different individuals. Because of her entrance into their closed-in world, and her acceptance of the two as both similar yet different, Hikaru eventually falls in love with her and becomes highly possessive of her in the process. However, he stops trying to get her when she starts dating Tamaki, even though he seems unhappy about the relationship.

Haruhi is described as a very important part of the twins' lives, as she is the first person to "enter their world" by being able to tell Hikaru and Kaoru apart with genuine reasoning and an understanding of who they are as individuals. Because of this and other factors, the twins grow to love her in a romantic way, but eventually "lose" her to Tamaki in the manga. They regard Haruhi highly, to the point that they describe the world as being full of idiots before her introduction into their life. Their closeness to one another is such that the twins give her a cell phone and each includes the others as part of their "Top Five" contacts. Hikaru doesn't realize his true feelings for Haruhi until his twin brother, Kaoru, helps him understand this. When Tamaki realizes his feelings for Haruhi too, Hikaru and Tamaki battle for Haruhi's affection and attention, such as having a contest to see who will give Haruhi a present she wants the most. Hikaru and Tamaki end up giving Haruhi the same gift, but Haruhi likes Kasanoda's gift best.

Quotes
"Feeling you have for each other will not be known unless you voice them," -Kaoru to Hikaru regarding  Hikaru's feelings in Operation Haruhi and Hikaru's First Date!

"Nothing can be communicated without words but if you really care about someone, even the smallest         details are important to notice," - Hikaru in Operation Haruhi and Hikaru's First Date!

Fandom
Fanfiction
 * https://www.fanfiction.net/s/3617782/1/Blossoming-love-Haruhi-X-Hikaru
 * https://www.wattpad.com/story/4153194-oblivious-love-hikaru-x-haruhi
 * https://www.fanfiction.net/community/Hikaru-And-Haruhi/93400/

Trivia

 * The Japanese Voice Actors of Haruhi and Hikaru are married
 * in real life.