Yeah I watched HXH around 4 years ago but it was after Naruto. I immediately saw the correlation between Sasuke and Kurapica. Also I hate to say it but the 4 Heavenly Kings greatly emulate the 4 disciples of Hokuto Shin Ken from Hokuto no Ken. Toriko/Kenshiro, Zebra/Raoh, Coco/Toki. The exception to this is Sunny/Jagi. Those 2 have absolutely nothing in common. I'd also say the majority of Bleach's plot emulates Hakusho, not just Toshiro/Hiei. Also Sasha from Seikon no Qwaser and Tasha Godspell both greatly resemble Allen Walker of D. Gray Man, but especially Sasha, down the the silver hair and red mark over the left eye. You also find a lot of correlations between Ao no Exorcist and D. Gray Man. And lastly Claymore emulates Berserk a lot. They both take place in a medieval time period, they are both swarming with demonic creatures, both main characters are armored and wield a giant long sword, both are almost devoid of humor, both main characters are very hesitant to form alliances but way down the road they do, both lost an arm, both have a berserker state, both series have very high amounts of gore and some nudity, both live primarily for the sake of revenge against 1 person and they go crazy every time they see them and so on. But don't get me wrong, I like all of the series I just mentioned, most of them a lot. It is difficult to be original, maybe impossible to be 100% original. It's just some emulations are blatantly obvious.