If I remember correctly - not 100% certain - his body just got transported back in time. At that epoch he was most likely a child or not even born. So he's the age he was in the future, plus maybe an unknown number of months in training
Me personally I really like this story , I haven’t gotten bored not once yet . I love everyone’s personalities , and I love the focus on the main characters love story , and how there’s a bit of the side characters love .
wow , I can’t stop cheesing like a school girl