Back when 2 of the 7 swordsmen went kyuubi mode Naruto sensed the disturbance. He wouldn't have easily just dismissed it, he would wanna check it out. We haven't saw anything else from him, it's just weird, he could've showed up by now in his new kyuubi mode i bet. I hope Kishi explains Naruto's whereabouts thoroughly. I hope he gets to kick some ass soon.