Leeseo

IVE's youngest member and one of its vocalists. Born in 2007, she debuted in her second year of middle school, making her the first 2007-born idol in Korea outside of kid groups.

Her real name is Lee Hyun-seo, born February 21, 2007, in Banpo, Seoul. Her stage name is just her real name with the middle syllable dropped, because she wanted something that sounded strong. Her brush with fame started absurdly early: at two, she was out taking the food waste to the curb with her mom when they ran into Han Hyo-joo filming nearby. The actress thought she was adorable, kissed her, and the whole moment aired on an entertainment news show. In second grade a piano competition got her scouted as a first-generation kid model for SM Entertainment, chosen from a 400-to-1 pool.

Being an idol was never the plan. In 2019, as a sixth grader, she was waiting for a drink at a department store café with her parents when a Starship Entertainment executive handed her a business card. The scout later said he couldn't forget how her eyes sparkled. She became a trainee on the spot and, two and a half years later, debuted with IVE in December 2021, the last member to be revealed.

Being that young turned into a steady supply of stories. For her first few months, youth broadcast rules meant she had to go home before any recording ran past 10 p.m., leaving the older members to finish without her. She's admitted it stung. Then came the generation-gap memes. She baffled Rain by not knowing how a slide phone opens, named Descendants of the Sun as the oldest drama she remembers, froze in front of Park Myung-soo's old-school phone keypad, and looked totally blank when Kim Jae-joong mentioned buying his dad a Hyundai Equus with his first paycheck. She also had no idea what Boys Over Flowers was.

Her signature nickname is "Baby Tiger." Back in trainee days, staff told An Yu-jin there was a young trainee who looked like a tiger cub: fierce eyes, very small human. She also winked so much during monthly evaluations that staff literally compared wink counts afterward, which earned her the "wink vending machine" title. Her take: it was the best stage charm she had at the time.

On stage she's a different person. Her voice is husky and clear at once, with a hint of nasal color, and her goal is to be instantly recognizable after one line. She got praise for nailing the bridge of I AM live at an encore, and she takes the most rap lines after the group's rappers. She's in the dance line too. During the debut era a fancam operator shoved the camera right into her face and she didn't even blink, which basically kicked off the "face-cam" fancam genre. Fans also love how precisely she hits the tick-tock move in LOVE DIVE.

From April 2024 to December 2025 she hosted SBS's Inkigayo. The peak came in February 2025: IVE won first place after their promotions had already wrapped, so Leeseo, sitting at the MC desk, sang the encore solo. The clip crossed a million views in six days and fans dubbed it her "first-birthday party." Three weeks later it happened again, and she handled the members' highest notes by herself.

She loves being the maknae. She claims to be the only person allowed to sit on the members' laps and plans to keep doing it until she's 29. She also sneaks onto members' and managers' phones to change their wallpapers to her own photos. The first member she met at the company was Liz, when Leeseo was in sixth grade and Liz was a middle school senior, and she still finds Liz's left dimple fascinating every time she pokes it. Rei knows all her secrets, and Jang Won-young once rescued her from a confusing hotel shower in Germany.

Turning twenty in 2026 made every IVE member an adult. That same year she graduated from Hanlim Arts High School and wrote the lyrics for her solo track Super ICY on the group's second full album. Her motto: "I walk slowly, but I never walk backwards." Japanese fans call her イソ (Iso).