Seen is a box of handwritten Christmas cards sent by university students that President Yoon Suk Yeol reportedly received, Tuesday. Courtesy of National Coalition of University Students for Impeachment of President Yoon Suk Yeol

"Dear Mr. President! Here are university students' handwritten letters to you! Happy end of the year! ♡♡♡♡♡♡♡"

Some 500 Christmas cards written and sent by Korean university students to President Yoon Suk Yeol arrived at the presidential residence in Hannam-dong, Yongsan District, central Seoul on Christmas Eve. Contrary to the cheerful message written on the cover of the envelope, the cards inside all contained criticisms of Yoon regarding his brief imposition of martial law on Dec. 3.

The National Coalition of University Students for Impeachment of President Yoon Suk Yeol announced Tuesday that the group had sent the cards to the president's official residence via the Hannam-dong Post Office in Yongsan District, central Seoul, on Monday morning. The cards were collected during a student rally held on Dec. 21.

The group also shared a confirmation message from the postal office verifying that the envelope was delivered to the presidential residence. The acceptance of the seemingly innocuous mail starkly contrasted with the president's recent refusal to accept official documents from the Constitutional Court and the summons sent by the Corruption Investigation Office for High-ranking Officials.

A university student writes a Christmas card to President Yoon Suk Yeol, Tuesday, which reads, "Damn Yoon Suk Yeol. Pay for your sins and go to prison." Courtesy of National Coalition of University Students for Impeachment of President Yoon Suk Yeol

"President Yoon has declined to accept all documents related to the impeachment trial by the Constitutional Court and the police's summons, yet he willingly received gifts and flower wreaths from his supporters on his birthday, Dec. 18," the group pointed out.

Some of the cards sent read, "You can't beat democracy" and "Pay for your sins and go to prison."

Another letter sent to the president read, "What right do you have to live comfortably in the presidential residence?" It continued, "While you sleep in a warm room and take hot showers, we spend sleepless nights on the streets, unable to even change clothes."

Since the impeachment motion passed at the National Assembly on Dec. 14, Yoon has refused to receive documents related to the impeachment trial sent by the Constitutional Court. Additionally, Yoon has not responded to the investigative agency's request for him to appear for questioning.

A post office vehicle is parked near the Presidential Office in Seoul's Yongsan District, Monday. Yonhap