A lot of people tend to forget something. Most of these another world style novels are based on medieval Europe, and the accepted practices/"morals" were different back then. Engagement & marriage at 13,14 was quite common. Multiple partners were also quite common. This was due to the fact that childbirth was quite the ordeal back then. A lot of mothers and/or their children didnt survive the ordeal or the ensuing childhood. There was also the issue that men were in short supply in some places/times due to some frequent skirmishes/wars back then.
he's actually 11 i believe.
nvm scratch that, he is 13. i was thinking of another manga.
em....this may be late saying this but...isnt he STILL just a thirteen year old boy on the outside?....(￣∇￣")