It does not mean they will wear nothing in the wedding, but it shows that these young couples are ready to get married without a house, without a car, without a diamond ring and without a wedding banquet, to show their commitment to true love.
服を着ずに結婚式をするのではなく 結婚する若者達が 家や車やダイヤの指輪や 披露宴などなしに 互いの真実の愛のみを確認するのです