Singer Yoon Ji sung left a message for fans ahead of his enlistment.

Yoon Ji sung said through message "I have to leave a message at the cafe because I have something I want to say to my fans grains first, I’m going to serve military services starting on May 14.” on his official fan cafe at midnight on May 25.

Yoon ji sung added word, "I feel sorry for my fans more often than anything else, Don't worry. I'll be healthy and safe.”

Yoon Ji sung made his debut as the project group Wanna One by appearing on Mnet's "Produce 101 Season 2," has tapped his role as a leader and friendly oldest brother who centers on the team with his unique positive energy. He was loved by fans for his hard-working character with both talent and personality.

After a year and a half of Wanna One activities ended, Yoon Ji sung released his solo debut album "Aside" in February, showing a further growth. Yoon Ji sung's emotions and voice as a solo musician, as well as his stable vocal skills that were strengthened through his seven-year trainee career, were recognized by the public.

He released his special album "Dear Diary" on April 25 and deliver a gift-like album to fans before joining the military. Dear Diary' is a diary-like album that candidly unravels the thoughts Yoon Ji sung has felt since his solo debut and was created to share his messy daily life with fans.

Yoon Ji sung held a special fan meeting "Dear Diary" at the Peace Hall of Kyung Hee University in Seoul on May 4 to 5 and met fans for the last time before joining the military.

▶ This following messages are Yoon Ji sung’s letter to his fans.

Hello, I'm Yoon Ji Sung.

Are you having a great day?

There's something I want to say to my fans grains first, so I leave a message at the café now.

I will join the army on May 14.

Some fans will be surprise and others will accept it calmly.

I'm sorry to my fans more than anything else.

I feel like I'm going through a lot of separation this year, so I'm sorry more than anything else.

But I'm not worried about my fans.

I think the fans I've seen so far are strong.

That’s why I'm not worried.

Don't worry about me.

I'll be safe in there until I finish the military services.

I have a lot of things to say, but I want you to remember that I'm so grateful and feel sorry to my fans.

We still have a lot of times to see. Let's talk about the rest at our fan meeting.

I'm sorry to say this before release of the album.

But I wanted to tell my fans first.

Let's meet again as soon as possible.

Thank you