Attorney Ko Young-han was appointed as a Justice of the Supreme Court in 2012 and concurrently served as the Chief Justice of the Court Administration Office from 2016. During his tenure as a Supreme Court Justice, he presided over landmark cases, including the full-bench ruling on the concept and requirements of ordinary wages, the resolution of the Samsung Motors bond recovery case, and the acknowledgment that methods and dosages of drug administration could be subject to patent protection. These cases, among others, left a significant mark on society.

After serving as a Supreme Court Justice, Attorney Ko joined Barun Law LLC, and he leverages on his extensive experience accumulated during his career as a judge when dealing with general civil, criminal, administrative, labor and intellectual property litigation cases to meet the needs of clients. His professional expertise spans corporate, financial, capital markets, M&A, insurance, intellectual property, fair trade, and corporate rehabilitation litigation and advisory service areas, as he draws on his prior roles as a presiding judge in the corporate and fair trade divisions of the Seoul High Court and as Chief Bankruptcy Judge at the Seoul Central District Court.

One of his notable successes in the Supreme Court involved a case where the plaintiff (a depositor) had deposited billions of won with the defendant (a credit union) through an agent. The deposited funds were later unlawfully withdrawn by the agent and the defendant's employees. In this case, the plaintiff sought damages from the defendant based on vicarious liability. While the first and second instance courts dismissed the plaintiff's claims, ruling that the deposit claims had expired due to the statute of limitations and that there was no proximate causation between the defendant employees' misconduct and the plaintiff's loss, Attorney Ko, representing the depositor in the appeal, secured a Supreme Court reversal and remand of the lower court's original ruling (Supreme Court Judgment No. 2020Da268265, delivered on April 28, 2022), establishing that the deposit claims had not expired and that proximate causation was recognized.

Attorney Ko also represented the plaintiff in a lawsuit against Hadong-gun concerning the transfer of title to a project site for the Gwangyang Bay Shipbuilding Industrial Complex Development Project, the largest investment in Hadong-gun's history. The plaintiff had entered into a land compensation agency agreement with Hadong-gun for the project. The lower court dismissed the plaintiff's claim, ruling that the statute of limitations for the plaintiff's title transfer claim had expired. Attorney Ko, representing the plaintiff, successfully argued in the Supreme Court that the lower court had misunderstood the legal principles concerning the starting point for the statute of limitations on the title transfer claim for rights acquired in the agent's name for the benefit of the principal. This led to a reversal and remand of the lower court's original ruling (Supreme Court Judgment No. 2022Da217117, delivered on September 7, 2022).

Meanwhile, in another case, Attorney Ko defended LH Corporation in an appeal case before the Supreme Court concerning the right of repurchase under Article 91 (2) of the Land Compensation Act. The plaintiffs, former landowners, argued that LH Corporation had failed to use a tract of land acquired through negotiated purchase for a land development project within five years, thus triggering their right of repurchase. Attorney Ko argued that the requirements for the right of repurchase should also consider the analogous application of Article 13 (1) of the repealed Land Development Promotion Act. The Supreme Court reversed and remanded the lower court's decision, holding that the conditions for repurchase rights under the Land Compensation Act were not met (Supreme Court Judgment No. 2021Da294889, delivered on August 18, 2023). This judgment relieved LH Corporation from paying a substantial repurchase amount.

In a family law case, Attorney Ko represented the defendant in an appeal case before the Supreme Court concerning the validity of marriage. The plaintiff of the case was a university professor, who had married the defendant after he became a widower. The plaintiff had married the defendant and they maintained a marital relationship for nearly 15 years, fulfilling spousal obligations despite not cohabiting with each other. The lower court had ruled that the marriage was invalid, citing that the defendant did not cohabit with the plaintiff and had registered the marriage only after the plaintiff's death, intending to receive survivor's benefits. Attorney Ko successfully argued that, i) the absence of cohabitation did not conclusively indicate an agreement to waive the obligation to cohabit as a married husband and wife, ii) even if the couple had continued to live apart after registering the marriage, this did not necessarily mean there was no substantive agreement to marry, and iii) the defendant's intent to receive survivor benefits was merely incidental to the marriage registration and did not negate the defendant's genuine intent to marry. The Supreme Court reversed and remanded the lower court's original ruling, upholding the validity of the marriage (Supreme Court Judgment No. 2020Meu13975, delivered on July 28, 2022).

Some notable fact-finding trial victories led by Attorney Ko include the following:

- J Asset Management vs. H Securities Case: In a case where J Asset Management and H Securities lost a deposit of approximately KRW 10 billion during the process of purchasing a hotel in the United States, Attorney Ko represented J Asset Management. He overturned the first-instance judgment and won the appellate court ruling, which held that the "additional deposit is the responsibility of the total underwriter (H Securities)" (Seoul High Court Judgment No. 2021Na204716, delivered on November 24, 2022). The appellate court's ruling was subsequently upheld by the Supreme Court through a judgment of dismissal without a hearing (Supreme Court Judgment No. 2022Da311873, delivered on April 13, 2023).
- Trademark Infringement Case for "Our Grandma's Tteokbokki (Woori Halmae Tteokbokki)": Attorney KO successfully defended the defendant, J Corporation, which owned 350 franchise stores, against W Corporation, the trademark holder of the famous franchise "Our Grandma's Tteokbokki." W Corporation filed a lawsuit claiming trademark infringement, seeking an injunction to prohibit trademark use and demanding significant damages. The court ruled in favor of the defendant, finding "no trademark infringement" (Seoul Central District Court Judgment No. 2023Gahap47495, delivered on January 19, 2024).
- Corporate Veil Piercing Case: Attorney Ko represented the plaintiff, who held the right to claim for investment and profit return related to a real estate development project. In this case, the shareholders of the debtor company had established a new company under a similar name, transferred the project right, which was the only asset of the debtor company, to the new company, and rendered the debtor company insolvent, effectively making the plaintiff's claims worthless. Attorney Ko argued for the piercing of the corporate veil and demonstrated the intent to evade debts. The appellate court overturned the first-instance ruling, holding that "the purpose of transferring the project rights to the newly established company was to evade debts, and therefore, the corporate veil of the debtor company should be pierced, holding the defendant liable" (Seoul High Court Judgment No. 2023Na2033734, delivered on April 3, 2024). The appellate court's decision was upheld by the Supreme Court through a dismissal without hearing (Supreme Court Judgment No. 2024Da239548, delivered on July 11, 2024).
- C Foods Rehabilitation Case: Attorney A represented C Foods, a company facing financial difficulties, in its rehabilitation proceedings. By utilizing a pre-packaged plan (P-Plan) and a stalking-horse M&A process, he secured a rehabilitation commencement decision and subsequent termination of rehabilitation proceedings within a record 45 days, enabling a swift recovery for the company.

Civil Cases
- Appeal case for damages related to the M&A of LS Mtron Co., Ltd.
- Appeal case for stock transfer claims related to the M&A of Namyang Dairy Products.
- Claim case for payment of goods and damages filed by Humasis Co., Ltd. against Celltrion, Inc.
- Appeal case for revocation of fraudulent trust filed by IBK Savings Bank Co., Ltd.
- Injunction case for prohibition of stock disposal involving Company I.
- Appeal case for insurance claims involving D Life Insurance Co., Ltd.
- Case seeking confirmation of invalid dismissal related to workplace harassment of an employee of E Credit Union.
- Appeal case for ordinary wage claims against Company D.
- Case involving wage claims against a taxi company regarding the validity of an agreement to shorten standard working hours between the taxi company and the union.
- Appeal case for wage claims involving Y Transportation regarding an agreement not to litigate over minimum wage.
- Appeal case for claims for service fees by Seum Co., Ltd.
- Appeal case for ownership transfer registration claims by ES Stone Co., Ltd.
Criminal Cases
- Appeal case involving the head of Jeonnam Dairy Cooperative for violation of the Public Official Election Act.
- Appeal case involving the chairman of J Construction for violations of the Act on the Aggravated Punishment of Specific Economic Crimes (Breach of Trust).
Administrative and Tax Cases
- Appeal case for cancellation of a refusal to designate a quarry for Company D.
- Case seeking the cancellation of a refusal to extend the waste treatment business license period for Company T.
- Appeal case seeking cancellation of a retrial decision denying relief for unfair dismissal related to workplace harassment involving an employee of E Credit Union.
- Appeal case for cancellation of property tax assessments involving JD Arc Co., Ltd., and others.
- Appeal case for cancellation of a decision revoking the designation of the Korea Music Copyright Association as a compensation-receiving organization.
Intellectual Property Cases
- Appeal case for damages involving the infringement of trade secrets related to the source code of a PACS system medical image viewer developed by Company I.
Constitutional Cases
- Jurisdictional dispute adjudication request regarding maritime boundaries between Namhae County and Tongyeong City.
- Constitutional review request filed by Dentist J regarding Article 5, Clause 2 of the Special Measures Act on Health Crimes.

Publications and Papers

Books
- Commentary on Civil Law, Obligations (XIV), Co-authorship, Pakyoungsa.
- Annotated Debtor Rehabilitation and Bankruptcy Act, Co-authorship, Law&Biz.

Articles and Journals
- Extraterritorial Application of Antitrust Law, Judicial Materials (87), Court Library.