This guy is way too trusting for someone that went from plantation slavery to being Shanghaied. When a stranger comes up to you with offer that seems too good to be true, you should at least be a little catious
And old man, I know you're desperate for your daughter to make friends, but you're clearly a man of means. You afford to be pickier, there are better options than a couple of malnourished teenagers sitting on a park bench
I guess I shouldn't think about it too hard but are the people in the other world also speaking Japanese? Or is there something else at play that makes it possible for everyone to understand each other?
Also, the slaver paid enough for one month's worth of food to buy Nanami but never bothered to get her Ludia value measured? That seems like a bit of an oversight, unless perhaps Ludia values can increase as you grow up?