But the thing that renji felt strange is the emotion of the so-called kyuubi he sensed anger, killing intent, loneliness,but he didn't sensed a single evilness from kyuubi a being who was told to be embodiment of the very evil itself; he sensed emotions since he was little; of course he trusted it more than he trust his eyes and ears, and so he started investigation, in 2 years he found every single bit of information he could find on kyuubi with the help of personal library of senjus, konoha public library and the personal library of uzumaki mito as well; during the process he found quite the bit about things like their ancestor indra, ashura, first ever uzumaki who is the creator of sole SS rank fuinjutsu there is in this world, sage of six path, rinnegan and the almighty clan of Ōtsutsuki, even though he found out everything he never act on it, he wasn't jinchiruki kushina is, it's her job and when she is ready to act he will be there protecting her, afterall its his job as her bodyguard and big brother.