Tanjiro is kind by nature and has been described by others as having very gentle eyes. He exhibits a great deal of determination and will not give up once he has a goal to achieve; the best example of this is his relentless quest to find a cure for Nezuko. He becomes the most powerful at the whole Kimetsu no Yaiba.. even more powerful than Yoriichi at the end. He doesn't easily give up.. you are the first friend of Tanjiro.. he is also a quick thinker while in battle and has unlocked the mark..