When investigations began into alleged drug use by these acquaintances, Yang reportedly fled to France in April.
Last month, he was sentenced to one year in prison and fined 2 million won.
Both the prosecution, which had sought a four-year prison term, and Yoo Ah In have appealed.
Yoo Ah Ins legal team argued, The defendant did not maliciously exploit loopholes in medical regulations.
Despite showing significant progress, the imposition of a prison sentence is excessive and unfair.
The next hearing is scheduled for November 19th at 11:30 a.m. KST.
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