Girl group AOA returned Monday with a powerful summer tune and a tearful press conference.

As the press showcase for the group’s new album “Good Luck” began at a concert hall in eastern Seoul, a teary-eyed Ji-min apologized for a recent controversy. She and Seol-hyun were heavily criticized when they were unable to identify the picture of a famous Korean historical figure on a TV show last week.

“I’m sorry that a regrettable incident happened right before our comeback. I’m very sorry,” she said.

Seol-hyun also shed tears at the end of the press interview, saying, “I will try to be more careful from now on.”

Member Choa shed tears as well as she talked about what a gift it had been to meet her teammates.

When asked what she considered to be the “luckiest” moment in her life, Choa began to cry as she replied, “I would have to say it was when I met the AOA members.”

The concept for AOA’s new album -- which comes 11 months after the group’s third mini album “Heart Attack,” released last summer -- features the girls clad in red swimsuits, sun-kissed and posing as lifeguards on a beach. 

“We tried to show a bold and confident side of ourselves,” said Choa on the girls’ new looks.

Title track “Good Luck” is a beat-heavy pop-dance tune composed by Canadian songwriter Matthew Tishler, and sings of a woman telling a man not to let go of her. The four other songs on the album are “10 Seconds,” “Cherry Pop,” “Crazy Boy” and “Still Falls the Rain.”

The album, released Monday, is available in two versions -- the “Week” version, which features the girls dressed as lifeguards, and the “Weekend” version, which depicts them in casual summer outfits. The group is composed of members Ji-min, Seol-hyun, Choa, Hye-jeong, Chan-mi, Yuna and Mina.

By Rumy Doo (doo@heraldcorp.com)