Sechskies had been preparing a comeback project with 'Infinity Challenge,' but when word got out about their surprise comeback on April 7, their project was pushed back to a later date. 'Infinity Challenge's production team instead planned an impromptu concert on April 14 at locations in Seoul and the surrounding Gyeonggi province. 

SEE ALSO: Comedian Park So Young and former baseball player Moon Kyung Chan tie the knot

Sechskies then put on the finale with the 'Infinity Challenge' crew at Seoul World Cup Stadium, which began at 8 p.m. It was reported that three hours before the grand show started, nearly 400 fans were already gathered at the venue despite no knowledge of Sechskies' unofficial comeback. When this reunion of Sechskies finally broadcasts, fans should be very excited as it's been 16 years since the group disbanded.