South Korean group Lucy delivered a thrilling and powerful performance to fans Sunday, successfully kicking off its first world tour.

The Seoul performance of the group's first world tour, “Written by Flower,” took place at the SK Olympic Handball Gymnasium in the Olympic Park in Seoul, on Saturday and Sunday. Audiences of over 10,000 people gathered at the concert hall over the two days.

The four members appeared on the stage in white outfits -- which was the pre-set dress code with fans -- and opened the last performance in Seoul with songs “Rolling Rolling” and “Knowhow.” The audience, almost completely dressed in white, cheered enthusiastically, welcoming the members to the stage.

“I never thought we could fill the Handball Gymnasium, so I'm incredibly moved. We put a lot of thought into showing a more diverse range of performances for this show,” said Sang-yeop, the band's vocalist and guitarist.

The band performed a series of cheerful, rhythmical songs, including “10 sec,” “Hero,” and “Unbelievable,” then changed it up for a number of special performances. Drummer Gwang-il, who was originally a vocalist before he joined the band, held the microphone instead of his drumsticks and performed “Perfect” and “Would You Dance with Me,” both of which he composed.

The solo performance of vocalist Sang-yeop followed as the next special performance. Sang-yeop captivated the audience with his emotional voice, singing "Prequel" and "Sequel," consecutively.

The band changed up the atmosphere again to perform the group's debut song "Flowering," which evoked a feeling of spring. The members then surprised the audience by unveiling a new song, "Nakhwa," which carries the meaning of a wilting flower.

"Everyone experiences moments when their strength and passion wane, but I don't regret those moments because ultimately, every moment of mine is precious. That's the sentiment behind the song," explained Won-sang.

"Nakhwa' is my favorite song from all of our albums so far. I'll see to it that it's officially released soon," Ye-chan said, eliciting cheers from the audience.

The four members then appeared on stage without their instruments, delighting fans with their cheerful dance moves before launching into the second act of the concert.

The second act, which began with intense red lighting, reached its climax during the performance of "Boogie Man."

The boogie man character in the song is depicted as a figure emerging from a closet, one that holds a strong desire for freedom having lived only according to predetermined rules. Ye-chan climbed onto the center stage and opened the closet. A child emerged from the closet and hugged Ye-chan, and he played the violin while holding the boy, captivating the audience's attention. After the child cut the string binding Ye-chan's hands, intense drum and guitar sounds filled the stage.

“The child symbolizes my younger days, and he liberated me, allowing me to do whatever I want," Ye-chan said about the meaning of the performance.

After performing various genres for about three hours, the members exited the stage, prompting fans to call them back for an encore by singing “Flowering.” Returning to the stage, Lucy concluded its fiery performance with “Ending,” “Someday in the 21st Century,” and “You Are My Light."

“We've become the artists we are today because you've listened to our music, gained strength from it, and supported us. We will work even harder to create songs inspired by all of you. We love you,” said Won-sang.

Violinist Ye-chan shed tears as fans applauded. “I sincerely love performing on stage. Thank you so much for supporting me in doing what I love.”

“If I have brought even a little comfort to you all, then I consider myself to be successful. I will work even harder to repay your expectations and support with better music,” said Gwang-il.

Lucy will continue its tour in Macau on April 6, in Taipei, Taiwan, on April 26, and in Tokyo on May 6. The band has also announced that it will visit North American cities after touring Asia.