He had made the visit to apply for a patent for a packaging box-related invention. Yunho is known as the 'God of Zeal' as he is known to take interest in various activities other than his singing career. In general, more than 95% of the patent applications at the Korean Intellectual Property Office takes place online as the applications are submitted electronically. However, TVXQ member Yunho decided to visit the office in person to fill out the application rather than doing it online.
According to the KIPO, "There are various methods to apply for a patent such as online application, mail-in application, and visitation. Yunho made a visit and applied for the patent in person in order to leave a video blog of the process."
In fact, Yunho is also known as "The King of Inventions" as he already holds various patents. The singer has repeatedly stated on television and other broadcasting shows that he has a hobby of inventing. Other than the patent he had applied for this day, he already has three patents under his belt.
On March 16th, Yunho applied for a patent relating to the face mask. He had designed a mask with a special lid on the front that can be opened and closed, allowing people to drink with straws without removing their masks. He revealed that he felt the discomfort of wearing the mask even before the COVID19 pandemic since he had to wear masks to cover his face as a celebrity.
The mask was quickly registered within 13 days after the application went through priority screening. In 2014, Yunho applied for a patent for his "Double cup" idea and a "Capsule-cup lid" which allows individuals to drink two drinks at the same time.
Starting this year, Yunho began to show his invention process through a YouTube channel series "King of Inventions". Yunho's invention will be registered and disclosed to the public as early as three months after the priority review.