A. On April 18, 201, the Plaintiff loaned KRW 30,000,00 to Defendant C as a credit service provider that completed the registration of credit business, and drafted a standard contract for loan transaction (hereinafter “instant contract”) with the Defendants, stating that “Defendant C, a joint guarantor, Defendant C, a debtor, 44% per annum (3.6% per annum), and a maturity of repayment as of January 17, 2012.”

B. From April 18, 201 to June 17, 2014, Defendant C paid to the Plaintiff KRW 41,040,000 each month (=30,000,000 per month x 3.6% per month) as interest under the instant contract (=38 months x 1,080,000).

C. Defendant C, on May 2, 2013, transferred the right to operate “E” jointly operated by Defendant C and D, and agreed that D will accept the Defendant C’s obligation under the instant contract (hereinafter “instant assumption of obligation”).

According to the Act on Registration of Credit Business, etc. and Protection of Finance Users and the Enforcement Decree thereof, where a credit service provider, who has registered a credit business, lends a loan to an individual or small enterprise, the interest rate shall not exceed 44% per annum from July 21, 2010 to June 26, 201, 39% per annum from June 27, 2011 to April 1, 2014, 34.9% per annum from April 2, 2014 to March 2, 2016, and 27.9% per annum from March 3, 2016, and the amended interest rate shall not exceed 27.9% per annum from January 25, 2010 to June 26, 201, and the amended interest rate shall not exceed the scope of "the amended interest rate under Article 9.1 of the Enforcement Decree of the Act to be applied only before the enforcement date of the amended interest rate under Article 9.2 of the Act."