The judgment below is reversed, and the case is remanded to Busan High Court.

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

1. citing the reasoning of the judgment of the court of first instance, the court below acknowledged the following facts: (a) upon citing the reasoning of the judgment of the court of first instance, E entered into the instant contract to sell the forest land in KRW 7 billion to F Co., Ltd. (hereinafter “F”) on September 20, 2006, and received KRW 650,000 won for the down payment; (b) without receiving the remainder of KRW 6.35 billion on September 27, 2006, E completed the registration of ownership transfer of the forest land in this case to F; and (c) on October 25, 2007, E waived waived KRW 97,80,000 among the remainder on the grounds that it was not well known to resolve the lawsuit for cancellation of the pre-sale registration of the forest land in this case; and (d) thereafter, E died on July 27, 2008 and the Plaintiffs jointly inherited its property.

In addition, the lower court: (a) on September 28, 2006, immediately after the conclusion of the instant sales contract, the Plaintiff: (b) jointly and severally guaranteed the F’s remainder payment obligation under the instant sales contract; (c) even after the death of the E, F continued the business of constructing and selling public rental housing on the land, such as the instant forest, etc. on the ground; (d) on November 26, 2009, the Plaintiff acquired and owns ownership of 5,355 square meters and two lots of land at a macro-si-si-si-si-si-si-si-si-si-si-si-si-si-si-si-si-si; and (c) after the death of the E, the Plaintiff and H jointly and severally paid KRW 5 billion to the Plaintiff A for the remainder of KRW 5 billion; and (e) in the lawsuit brought against the Plaintiff F and H, it appears possible for the Plaintiffs to recover the remainder payment obligation under the instant sales contract from the Plaintiff’s remainder of KRW 700,000,000,00.