On the morning of December 12 KST, Yoo Ah In faced his first trial at Criminal Agreement Division 25-1 of the Seoul Central District Court, where he was charged with multiple offenses, including habitual drug use, smoking and instigating marijuana, instigating evidence destruction, violating the Medical Service Act, and fraud.

Originally scheduled for November 14 KST, the trial date was changed due to a request from the defense attorney. In this formal trial appearance, Yoo Ah In attended the court proceedings. Appearing for the first time since his indictment, Yoo Ah In was seen with longer hair and wearing a black coat, shirt, and pants.

Before entering the courtroom, Yoo Ah In addressed reporters' questions, expressing remorse, "I am sorry for causing concern to many people. I will faithfully participate in the remaining trial process and do whatever I can. I would like to apologize once again to those who were greatly disappointed and suffered a lot of damage because of me."

When asked about the reason for the trial date postponement, Yoo Ah In replied, "I think there were circumstances related to the lawyer," while refraining from responding to questions regarding the charges, such as admitting to habitual drug use 181 times.

During the trial, Yoo Ah In's defense acknowledged, "We acknowledge that the defendant engaged in the common crime of smoking marijuana," but argued that "some of the charges, such as teaching marijuana smoking and destroying evidence, differ from the facts or are exaggerated."

Furthermore, Yoo Ah In’s defense stated, “There are many areas to review in-depth regarding the facts and legal principles. I will give my opinion on that matter after thoroughly reviewing the evidence,” indicating a comprehensive examination of the case.

Yoo Ah In faced charges of administering propofol 181 times from September 2020 to March of the following year and illegally prescribing and acquiring sleeping pills in someone else's name from May 2021 to August of the same year.

In his first summons appearance in March, Yoo Ah In had stated, “I shared all the facts that I could reveal. I deeply regret that I am in this position due to an unfortunate incident and have disappointed many people who have supported me.”