S2IT drop 'Blue Crush' six months after debut, with MV to follow on Sept. 15

S2IT are back — and they brought receipts

S2IT debuted March 14 with What I Want. Six months later, the five-member group—Hyobin, Sea, Haru, Yeonsu, and Seungbi—returned with Blue Crush, a digital single released September 7. That afternoon and evening, they held a media showcase and a fan showcase at the Hyundai Department Store Uplus Illusta Stage in Sinchon, Seodaemun-gu, Seoul. The music video arrives September 15.

Blue Crush is built on an intense Jersey club rhythm and hyper pop production. A music-box bell sound opens the track. Then tension builds. The song expands from a dreamlike atmosphere into explosive energy, described as unpredictable throughout.

What the members said at the showcase

Haru disclosed she lost weight down to 33 kg during preparations. She framed the comeback in terms of growth: "At debut, the goal was to show rookie-like boldness because we didn't know anything. This comeback's goal is to show a more mature, grown appearance."

She spent six months in rehearsal focused on group harmony, facial expressions, and eye contact—all aimed at projecting aura on stage.

Hyobin zeroed in on the track itself: "The chorus part bursts impressively. It's a song you can listen to without getting bored." On what separates S2IT from the pack, she offered a more measured pitch: "step-like charm," meaning incremental, visible growth rather than instant polish.

Sea and Yeonsu pitched the timing directly to listeners. Blue Crush "perfectly matches the current weather," they said, and they want people to reach for it "when you don't want summer to end." Yeonsu added a candid aside about the recording process—she could eat freely in the studio because vocal volume required it, making recording her favorite part of the whole comeback cycle. (Relatable, honestly.)

The single carries what the group describes as their change and growth since March, compressed into one hyper pop track and a showcase stage in Sinchon.