All appeals are dismissed.

Of the costs of appeal by the Plaintiff, the costs of appeal are assessed against the Plaintiff, Defendant E Trade Union, and K.

The grounds of appeal are examined (to the extent of supplement in case of supplemental appellate briefs not timely filed).

1. Judgment on the Plaintiff’s grounds of appeal

A. 1) The Trade Union and Labor Relations Adjustment Act (hereinafter “Trade Union Act”)

According to Article 29-2(1) of the Trade Union Act, workers may freely organize or join a trade union (Article 5). A representative of a trade union may request an employer to conduct collective bargaining on behalf of the trade union or its members (Article 29(1)). However, in cases where at least two trade unions exist in one business or workplace regardless of their structural form, the representative of a representative bargaining trade union determined in accordance with the procedures for simplification of bargaining windows shall demand the employer to conduct collective bargaining (main sentence of Article 29-2(1). The provision that the Trade Union Act introduces the system for simplification of bargaining windows for multiple trade unions so that a number of trade unions can promote collective bargaining procedures by effectively resolving the problems, such as the anti-competitive and conflict between the trade union or between the trade union and the employer when the multiple trade unions exercise their independent collective bargaining rights, the main purport or purpose of establishing an efficient and stable collective bargaining system without any reasonable ground (see, e.g., Supreme Court Decisions 2016Du36956, Oct. 31, 2017; 2013Du18).