Nagomi realizes she can just have fun with cosplay, just like Ririsa. When the two cosplayers meet later on, a new friendship blooms.
A religion is a belief system with rituals. The missionary kopimistsamfundet is a religious group centered in Sweden who believe that copying and the sharing of information is the best and most beautiful that is. To have your information copied is a token of appreciation, that someone think you have done something good.