Ok, the title seems to be a question, so I will answer. XD This is Kaoru. I know because he parts his hair the same way I do, and Hikaru parts his hair the opposite way, which is the same way my twin parts her's. Also, if I'm thinking of the correct reference picture, it was Kaoru in that pose.
Even I, who drew the pic don't know if it's Kaoru or Hikaru XD hahaha. Well, since a lot of you commented that it's Kaoru, the one i drew then, is Kaoru! ^___^ hahaha, thanks for commenting. XD