A. The Plaintiff is a management body established under the Guro-gu Seoul Metropolitan Government Act on the Ownership and Management of Aggregate Buildings (hereinafter “Aggregate Buildings Act”).

B. C purchased the above A-4th floor D (hereinafter “instant shopping mall”) on October 15, 2003, and completed the registration of ownership transfer on December 4, 2007.

C. C did not pay the management expenses for the instant commercial building for 26 months from November 2010 to December 2012, and for 36 months from March 2014 to February 2017.

On March 19, 2015, the Plaintiff filed an application with Seoul Southern District Court for a payment order seeking payment of KRW 17,083,366 and delay damages on the grounds that C had unpaid KRW 17,083,336, total management expenses from November 2010 to December 2012, and from January 2014 to February 2015.

The above payment order was finalized on April 18, 2015 because C did not object to a payment order issued.

E. Meanwhile, the Defendant was awarded the instant commercial building in the Seoul Southern District Court E Real Estate Auction case and paid the price in full on March 24, 2017, and on April 4, 2017, the ownership transfer registration was made in the Defendant’s future.

F. On April 25, 2017, the Plaintiff sent a letter verifying the purport that the former owner C shall pay the unpaid management expenses of KRW 19,711,547 to the Defendant by May 1, 2017 pursuant to Article 16(3) of the Commercial Building Management Rules and the Supreme Court precedents, under the title “Guidance on the Payment of Management Expenses”, and the said notice was served on the Defendant around that time.

G. On April 28, 2017, after receiving the above notice, the Defendant sent a notice to the Plaintiff to the effect that the Supreme Court precedents apply when the management body made best efforts to recover unpaid management expenses, and that the Plaintiff cannot respond to the cause attributable to the collection of unpaid management expenses.

H. Of the Plaintiff’s management rules, the parts pertaining to this case are as follows.

§ 13.