A. The act of mistake of facts and misapprehension of legal principle constitutes self-defense.

B. The sentence of an unreasonable sentencing (1.5 million won of a fine) imposed by the lower court is excessively unreasonable.

2. Determination

A. Determination of facts and misapprehension of legal principles regarding the assertion of mistake of facts) An act of defending the present infringement of one’s own or another’s legal interest is not punishable if there are reasonable grounds, and when the act of defending goes beyond the said degree, the punishment may be mitigated or exempted under the circumstances (Article 21(1) and (2) of the Criminal Act). However, in order to establish self-defense as stipulated under Article 21 of the Criminal Act, the act of defending the victim by taking into account all specific circumstances, such as the type, degree, method of infringement, and type and degree of legal interest infringed by the act of defense, should be socially reasonable (see, e.g., Supreme Court Decisions 92Do2540, Dec. 22, 1992; 2005Do3940, Sept. 30, 2005; 2005Do15, etc.). Meanwhile, the defendant’s act of defending the victim’s own right of attack against the victim’s act of attack (see, 200.