Kenma teleported back to time. Your. kenmas bestfriend and you've had a bad childhood...kenma was gonna fix all that...help you and stay by your side...he saw your little self..a five year old crying...he went up to you and knelt down "Hey...it's okay...I'm here for you..you don't need to cry.." He haven't met him yet at that time...so you didn't know who he was