This year's 'That Winter' concert began ticket sales on September 25 and is ranked number 1 for most reserved tickets.

Interpark announced that Kim Bum Soo and Park Jung Hyun's duo concert is the most anticipated concert for the last of this year.

Although this concert is set for Christmas time, reservations have already started.

These two singers received much love and attention from their appearance on "I am a Singer" Season 1. 

This year's "That Winter" concert hopes to capture the hearts of fans with their amazing vocals. 

On top of performing their hit songs, they will also perform new songs that they have never shown live before. 

This concert will be held on December 23-25 for a total of 4 performances.