Singer Psy kicked off his "Summer Swag" concert series with music, water and a new artist in the first performance of his national tour held Friday and Saturday at Jamsil Olympic Main Stadium, southern Seoul.

The singer's "Summer Swag" concert series, marking its seventh season, features upbeat performances by the singer and plenty of water sprayed at the audience to fight the heat.

"This is the first time in four years for 'Summer Swag' to be held without masks," Psy said Friday. "My heart tingles every time I hear you shout."

Psy performed his best-known dance tracks including "That That" (2022) featuring BTS's Suga, "New Face" (2017), "I Luv It" (2017), "Gangnam Style" (2012) and "Champion" (2014).

Singers Jessi and Hwasa also took part as guests.

In a surprise move, Hwasa, singer and rapper of girl group Mamamoo, signed an exclusive contract with Psy's agency P Nation on the stage. Psy laid out the papers on stage and Hwasa signed them, with the two hugging afterward.

"Hi, I'm Hwasa, who just became a singer at P Nation," she said to the excited crowd. "That was the real deal just now. We only finished reviewing the papers today."

The "Summer Swag" tour will continue in: Wonju, Gangwon on July 8; Yeosu, South Jeolla, on July 15; Suwon, Gyeonggi, on July 22 and 23; Boryeong, South Chungcheong, on July 29; Iksan, North Jeolla, on Aug. 5; Incheon on Aug. 12; Daegu on Aug. 19 and 20; and end in Busan with performances on Aug. 26 and 27.

To find out more about Psy and Hwasa, visit https://celebconfirmed.com/

BY YOON SO-YEON [yoon.soyeon@joongang.co.kr]