The value of Korean Won against U.S. Dollars had been increasing stably in a consistent manner until the end of 2007. The value of Korean Won, however, started to plummet suddenly in 2008 as the global financial crisis occurred as a result of the sub-prime mortgage problem in the U.S. and other factors. Such dramatic change in the value of Korean Won triggered a sharp rise in disputes involving over-the-counter derivatives products. The KIKO litigation is a major example of such disputes. Disputes involving KIKO products began in 2008 as the Fair Trade Commission conducted its regulatory review of the contracts used for KIKO transactions. Subsequently, the disputes went through a dispute mediation process at the Financial Services Commission and even prompted the Financial Supervisory Service to audit the banks that had sold the KIKO products. The KIKO controversy was also the subject of inspection by the National Assembly during its annual audit of the executive branch of the government. Civil lawsuits, including preliminary injunction and main civil claim cases, began to appear in late 2008. After two years of intensive review, courts have ruled on 200 or so civil cases at trial level. The trial rulings covered unprecedented in-depth analyses of issues relevant to derivatives products and financial engineering. This paper summarizes the judicial view of main issues of the KIKO litigation as reflected in the trial rulings and discusses its implication. Specifically, this paper focuses on the following main issues of the trial rulings: (1) whether KIKO products are structurally fair (Chapter II); (2) whether KIKO products are suitable for foreign exchange hedging (Chapter III); (3) what zero cost means (Chapter IV); (4) whether the amount of margins earned by banks under KIKO contracts is appropriate (Chapter V); (5) whether it is permissible to terminate KIKO contracts based on the change-in-circumstances theory (Chapter VI); and (6) whether KIKO contracts constitute "standard terms and conditions" (Chapter VII). It is understood that the courts have made correct decisions in the KIKO civil lawsuits by poignantly recognizing problems with numerous arguments made by plaintiff companies which are inconsistent with basic principles underpinning the financial market, derivatives products and hedging systems. The fundamental cause of the KIKO controversy was the abrupt rise in the foreign exchange rate, which no one had foreseen or could control. Thus, it is undesirable to transfer the consequence of or responsibility for the rise in the foreign exchange rate to banks through litigation. The challenge being faced should be resolved through providing credit support to small to medium-sized companies as a matter of national concern or mitigating negative side effects of the government goal of maintaining a high foreign exchange rate for Korean Won from a financial or industrial policy perspective.