The current Trade Union Act not only considers civil and criminal misbehavior as unjustifiable labor union activities but also prohibits unfavorable treatment of employees (such as dismissal) for justifiable union activities.
However, if union activities take place during working hours or within the company premises, then disputes may arise concerning the employer's right to supervise or manage labor and facilities.
The scope of labor union activities, which are under protection of the Trade Union Act, is not specified by law, but suggested by judicial rulings as follows:
- First, the behavior must be seen as an activity on behalf of the labor union or to obtain implied authority or approval for the labor union (Characteristic).
- Second, the behavior must be necessary to maintain and improve the employees' working conditions and to enhance their economic and social status, and must assist in enforcing employee unity (Purpose).
- Third, the activity must be outside working hours, except for special provisions granting permission to the contrary in the rules of employment or collective agreement, or except for repeated labor practice or the employer's consent (Time).
- Fourth, union activities inside the workplace shall follow reasonable conditions based upon the employer's right to manage the facility and the activities must not involve violence to persons or property (Method).
These criteria shall be the standards for labor union activities if there are no specified rules in the collective agreement or if there are disputes on interpretation of the agreement. In order to prevent such conflicts, it is advisable to stipulate concretely, in the collective agreement, the admitted scope of labor union activities and procedures during working hours or within company premises.
In principle, union activities shall be arranged outside working hours so as to cause no disturbance in the company's regular work. Otherwise, union activities shall be approved by the employer, unless there is special approval through collective agreement, etc. Specific regulations in the collective agreement are highly recommended.

Ⅰ. Internal Activities of a Labor Union

1. It is not justifiable to prohibit a former union member from rejoining the union.

1) To qualify for union membership, union members shall be the employees stipulated under Item 1 of Article 2 of the Trade Union Act, shall not fall under Item 4(a) of Article 2 of the Act, which renders ineligible for union membership those who have the status of an employer or a person representing the interests of the employer, and shall be determined autonomously by the labor union’s bylaws.

2) According to Article 5 of the Trade Union Act, employees shall be free to join a labor union or leave it. The joining procedures shall be stipulated in the bylaws of the labor union concerned. In cases where a labor union organizing a particular company’s employees rejects membership applications or obstructs union membership by delaying procedures(e.g., requiring the approval of the labor union chairman), the principle is to interpret their having been recognized as fully qualified member of the union.

2. A labor union is free to join or withdraw from an associated organization of labor unions.

Just as a qualified employee can organize, join or depart from a labor union on his/her own volition, a union is also free to join or withdraw from an associated organization as long as such decision is made in an independent and democratic way.

3. It is null and void if a bylaw or election management rule stipulates indirect selection methods in order to prohibit labor union members from selecting delegates directly.

Article 17 of the Trade Union Act regulates that delegates in the council of delegates, on behalf of the general assembly, the highest decision-making body, shall be elected by direct, secret, and unsigned ballot. The purpose of this guide is to let the union members be engaged in decision-making about the organization and operations of the labor union and to promote democracy inside the labor union. Accordingly, it is null and void if a bylaw or election management rule stipulates an indirect selection method and prohibits labor union members from selecting delegates directly, except in special situations.

4. Criteria to determine whether a union activity is justifiable or not.

A union activity is justifiable when it is reasonably regarded as an activity of the union or is authorized or approved, explicitly or implicitly, by the union; it is aimed at maintaining or improving working conditions, promoting the economic and social status of employees and bringing the employees closer to one another; it is done outside of working hours, except when the collective agreement otherwise prescribes or the employer has approved union activities during working hours; and, if it is conducted within the premises of the company, it complies with the rules and restrictions based on the employer’s right to control the facilities at the workplace and is not an act of violence or destruction.

5. If some of a union's members are against a certain decision or policy of the union, the activity performed to express such opposition is not a union activity.

If certain union members did not accept the decision or policy of the union and, to express such opposition, took an action, for example, by handing out printed matters criticizing the decision or policy, such action is arbitrarily initiated by those union members, and not taken under the agreement of the union members. Accordingly, such action is not seen as a union activity, except when there is a particular reason to regard it as either being essential to the union activities or having been approved by the union itself.

6. If some of a union’s members are against a certain decision or policy of the union, the activity performed to express such opposition is not a union activity.

If certain union members did not accept the decision or policy of the union and, to express such opposition, took an action, for example, by handing out printed matter criticizing the decision or policy, such action is arbitrarily initiated by those union members, and not taken under the agreement of the union members. Accordingly, such action is not seen as a union activity, except when there is a particular reason to regard it as either being essential to the union activities or having been approved by the union itself.

Ⅱ. External Activities of a Labor Union

1. Protection of the Employer’s Right for Order within the Company

1) A labor union officer had been wearing a vest decorated with union propaganda. Although the company had warned him several times that he would be punished according to company regulations if he continued to wear the vest during working hours, he disregarded the warnings. Therefore, the company decided to discipline him by suspending him from office for two months. That is not unfair labor practice.

2) Although a behavior is partly related to union activities, if the disciplinary dismissal was for a reason stipulated clearly in the rules of employment, then the dismissal is not an unfair dismissal.

3) Where the company dismissed an employee due to his anti-government agitation, promotion of distrust, lying on a resume, etc., if the company’s dismissal was not in retaliation for his union activities, but to take disciplinary measures against the harm to company order, then this is not an unfair labor practice.

4) Despite an employee’s status as a labor union officer, so long as there is no evidence that the company took disciplinary action on account of its dislike for the union, then the action cannot be said to be an unfair labor practice.

5) If disciplinary dismissal for an illegal industrial action and an employee’s contempt for the representative director was justifiable and not nominal, then it is not regarded as an unfair labor practice.

2. labor union activities

1) If a union member does not follow the union’s decisions, as determined by the decision-making process of the labor union, or if the union member opposes or criticizes a labor union decision or policy, the behavior is considered voluntary and a purely personal activity, and is not considered union activity.

2) Running for a position as a union delegate is clearly engaging in union activity. Furthermore, applying to the Ministry of Employment and Labor for unpaid allowances such as bathing allowance and reserve army training allowance pursuant to the rules of employment shall be considered union behavior if the purpose is to improve the employees’ working conditions and enhance their economic and social status, which can be interpreted as behavior to obtain the implied authority or approval of the labor union. This is justifiable and permissible union activity.

3) Even though it is company policy to require the company’s prior approval or permission to distribute a handout, this requirement cannot prohibit every union activity including justifiable activities to maintain and improve working conditions. Whether such activity is justifiable shall not only be judged by the company’s position but also other factors, such as the handout’s contents, number of pages, time and method of distribution, effect on the company or the work, etc.

4) Distribution of handouts during non-working recess hours is permissible even if the union member did not obtain prior permission, unless the distribution negatively affects other employees’ work, obstructs free use of their recess hours, or concretely corrupts order within the corporation. Although the handout distributed by a union member is designed to promote working conditions, if its content creates extreme distrust or hatred toward management and endangers public morals by distorting or exaggerating conditions, the employer’s decision to dismiss the employee for disciplinary reasons is justifiable and not an unfair labor practice.

5) If some contents stipulated in the handout damage the character, honor, reputation, etc. of other employees or some parts of the document are falsified, exaggerated or distorted, then if the purpose of distributing the handout was not to infringe on other employee’s rights or interests, but to maintain and improve working conditions, to promote employee welfare, and to enhance their economic and social status, and if the content of the handout was true as a whole, the distribution of the employee’s handout is a justifiable union activity.

6) A distributed handout contained content slandering the company, and may have caused hostile feelings against the company. It was not handed out directly to the employees but was spread over the employer’s plant in secret. Even though it was distributed during the labor union’s election campaign of delegates, this handout may have brought concrete danger by infringing on the employer’s right to manage his facility and violated corporate order, so it is not justifiable.

7) The company stipulated in its rules of employment that handouts distributed inside the workplace shall obtain the employer’s prior approval and the company may take disciplinary action against an employee who violates this rule. The rule is be invalid simply because it might violate the provision of the Constitution guaranteeing freedom of speech.

8) Although a labor dispute was resolved, the company’s operations returned to normal, and the union repeatedly urged a union member to come back to his job, he did not return to his driving job for an extended period because he was still participating in labor union activities and trying to disrupt the operations of the company. If the company dismissed him for the above reason, this decision is hard to categorize as an unfair labor practice taken to retaliate against his union activities(such as participating in previous strikes).

9) In cases where the labor union in a company with a day and night shift has to hold a general meeting to discuss the pros and cons of an industrial action, and informs the employer of the general meeting, although the general meeting is held during working hours, it is permissible union activity.

3. Position and activities of a labor union officer

1) When an employee received a personnel order to change jobs or transfer to another department under the employer’s rightful authority, the employee was absent from work for over 20 days and disobeyed the personnel order, concluding that the company was retaliating against him for his demands for improved working conditions. Since the behavior was a severe violation, the termination of his labor contract was justifiable.

2) A labor union’s full-time officer basically maintains labor relations with the employer, keeping his status as an employee, but he is considered suspended from duty and exempt from his work obligations. On the other hand, as the employer implements a training program during working hours, and the employees are obligated to attend, such occasion is like providing work to the company. Unless there is a special provision in the collective agreement stating otherwise, it is difficult to treat participation in the training as wrong.

3) When a union member was absent because he was campaigning for election as a labor union delegate, this is not a justifiable reason for absence from work and therefore is cause for dismissal by the company.