"No matter the cost"
-- Hartea to his brother Harashi In Volume 10, chapter 4
Hartea 「はｒてあ」Is the second son of IDka family, and the child with the least amount of demonic energy inherited from his mother, he's the main protagonist of the series as well.
Hartea is a decent height for his age, but he is a little short compared to other characters, he has Spiky Black hair, and light blue eyes, (eyes of those of a cats). He lacks facial hair, he also is seen with a long black coat with fur on the right side of it -- with a black T-shirt under it (School uniform shirt) He has pants that are cut off at the bottom to show his ankles, and he wears standard blue and black shoes.
During the Castle Of Legends , Hartea's hair is dyed a little bit white in the front, some of his hair is also lowered down to cover his right eye. He wears a black tuxedo with a white shirt under it, with a tie matching the color of his tuxedo, he wore pure white shoes, that look goes away after the event is over.
Hartea is seen as a sad and lonely person in the beginning of the series, but around others he is a very cheerful and excited person, who worries a lot on others and usually pins their mistakes, or injuries on himself.
He is later on shown as a extremely cocky and confident individual who is a little bit perverted, and extremely reckless, but also a very nice person -- Protecting and complimenting others when their in trouble, despite his current appearance or situation.
Hartea is shown a couple of times in the series with a darker side of him, named Akuma. This side is always doubting Hartea, and making fun of him for mistakes he has made, or worries that start to raise up, or whenever he has lost all signs of hope. Whenever Hartea is in a tough situation, or becomes angry -- Akuma appears.
- IDka Knife 「 伊dかkにふぇ 」A weapon he receives from Kakashi early on in the series (Volume 3, Chapter 2 "The IDka Knife") The knife was from a strange salesmen, the stronger Hartea becomes, the stronger the knife becomes, and only Hartea can activate it.
Demon Blade 「 でもンbぁで 」A blade passed down to him from his mentor Hikari , The demon blade feeds off of Demonic energy, and takes the form of a full sword once demonic power is fed into it. The demon blade has the form of just a normal handle, with just a small piece of the actual blade on it -- but is able to block attacks with the lenght of a normal sword, and counter-attack, attacks. He is rarely seen using this weapon.
Hartea and Harashi have a strong brotherly bond, with Hartea enjoying every single moment with his brother -- even if it isn't a big one, they both defend each other in fights or tough situations, and Hartea tries to make his brother engage in conversation with any female he sees passing by.
Hartea and Kakashi have a somewhat "Distant" Relationship, Kakashi saved Hartea from being ran over by a moving truck, and after the Blockade Tournament Hartea starts to develop feelings towards her that she is completely unaware of, Hartea always gets jealous when someone touches or kisses Kakashi -- and his usual reaction is to stab them.