Hey there.

I don't know who is Aine or Toujin. But are you talking about Sage world or Great ninja war (Group event) ?

If you are talking about Great ninja war, there is one rule. Only players that are part of the group for at least 7 days are allowed to join Great ninja war. That means if they joined, lets say only 4 days before Great ninja war, they can't join till they will "pass" this 7 day rule.

Oh that is correct. But he didn't say it is his first group. : )