2PM celebrated Chansung's 23rd birthday (Korean age: 24) and their recent #1 ranking on the Oricon Charts with 10,000 fans at their Budokan concert in Japan on the 13th.

Fans held a surprise event for Chansung with their fan lights and messages to celebrate his birthday. Chansung, who is currently busy with his filming schedule for MBC's '7th Grade Civil Servant', thanked them for their touching support.

Fans were also able to share the excitement of 2PM's success on Oricon. Taecyeon, who was the first to hear the news, surprised the other members on stage, and they all couldn't contain their joy.

2PM is currently on their '2PM ARENA TOUR 2013 LEGEND OF 2PM'. The boys will also be holding a Tokyo Dome concert on April 20th-21st.

Happy Birthday, Chansung!