tripleSfans

Members/S23

Next · S24 JiYeon
SeoAh 서아
Source · @triplescosmos Instagram post

S23 · Pale Sky BlueMaknae

SeoAh서아

Jeong Hae-rin

Winter cover · Team Blue C · Merry & Happy · official 24 Sep 2026 · @triplescosmos

Active DIMENSION
Neptune
Debut DIMENSION
Glow
Birthday
Fri 11 Jun 2010 (16)
Position
Vocalist · maknae
Nationality
South Korea
Birthplace
South Korea
Height
158 cm
Blood
O
MBTI
ISTP
Revealed
Mon 1 Apr 2024
Season
Divine01 · S21–S24
HAUS now
MOD Forest HAUS · 4-bed

YOUTUBE

SeoAh.SSS

SeoAh.SSS

3 Apr 2024 · @triplescosmos

Opens on YouTube ↗

Opens on YouTube. Nothing plays on this page.

01 · Arrival

S23 SeoAh is the maknae. Born 11 June 2010, legal name Jeong Hae-rin — WAV Gravity named her SeoAh so the roster would not hold two Hye/Hae-rins next to S2 Jeong Hye-rin. Pale sky blue, about 158 cm, shortest and youngest SIGNAL. A Glow vocalist who absorbed dance on contact and later joined Neptune. Fast debut, no trainee years. The group greeting hits different when she says it. About nine years and four months younger than eldest YooYeon.

02 · On stage

Pale sky blue, ~158 cm, shortest and youngest. Glow vocalist who absorbed dance on contact, later Neptune. Design: the clock’s last hour, drawn small.

03 · SIGNAL

SeoAh.SSS. GLOW profile | SIGNAL 240504. OT24’s youngest teaser.

DIMENSIONs

OFFICIAL · @triplescosmos

Official posts on X

From the official @triplescosmos account on X. The photo stays on X. This card opens that post.

Winter cover · Team Blue C · Merry & Happy · official 24 Sep 2026

X · @triplescosmos · Thu 24 Sep 2026

Winter cover song — Merry & Happy (TWICE). Team Blue C, sun & neptune.

tripleS Event Gravity Winter Cover Unit Final Result Merry & Happy — TWICE (트와이스)

Open official post ↗

X · @triplescosmos · Wed 23 Sep 2026

Winter Cover Unit final result: Team Blue C — sun & neptune

tripleS Event Gravity Winter Cover Unit Final Result Team Blue C — sun & neptune

Open official post ↗

X · @triplescosmos · Sun 23 Aug 2026

Ballad Dimension 2 lineup: JooBin, SeoYeon, ShiOn, SeoAh

tripleS Grand Gravity Ballad Dimension 2 Final Lineup JooBin SeoYeon ShiOn SeoAh

Open official post ↗

2 · DIMENSIONs

DIMENSIONs

NeptuneGlow

Habits the camera already knows

Born 11 June 2010. Legal name Jeong Hae-rin — WAV Gravity named her SeoAh so the roster would not hold two Hye/Hae-rins. Fast debut, no trainee years. The group greeting hits different when she says it.

Before MODHAUS

Youngest member. Stage name chosen because her given name collides with HyeRin. Zero trainee period.

Notes

  • Maknae. Born 2010.
  • Legal name Jeong Hae-rin — stage name SeoAh chosen to avoid collision with S2.
  • Shortest member (~158 cm).
  • Glow and Neptune. Fast debut, no trainee years.
  • Winter cover, Team Blue C — sun and neptune. Song: Merry & Happy. Official 24 Sep 2026.
  • Neptune — Fly Up under SeoYeon, with the maknae on the water planet.
  • Glow original four. Inner Dance.
  • Stage name from Gravity, not from the company alone.
  • The clock's last hour, drawn small.

How she was batched

  • Cream01 injection

    Four days. Four members. No Gravity.

    NXT (Lynn, JooBin, HaYeon, ShiOn) arrived in four consecutive December days and debuted the same week with Just Do It. Glow (ChaeWon, Sullin, SeoAh, JiYeon) closed the clock in April 2024. These batches were not voted — they were inserted so OT24 could exist on time. Team dynamic: the veterans had to make room in the HAUS footage overnight. SIGNAL’s job that month was introductions, not games.

  • msnz · four planets

    Moon, Sun, Neptune, Zenith — six each.

    WAV named the 2025 OT24 umbrella Magic Shine New Zone, then the roster split into four 6-member planets on one record, Beyond Beauty. Sullin’s Moon, Xinyu’s Sun (Bubble Gum Girl), SeoYeon’s Neptune, HaYeon’s Zenith. Team dynamic: four captains, four temperatures, monthly Japanese originals toward 2027. Sun is the aero-pop flag this archive had been skipping; the other three planets are the rest of the sky.

Group albums she stood on

Her clock

  1. Wed 3 Apr 2024 · Reveal

    S23 SeoAh

    Maknae, born 2010. Legal name Jeong Hae-rin — stage name later chosen by Gravity so it does not collide with S2. Teaser: SeoAh.SSS.

  2. Fri 21 Jun 2024 · Dimension

    Glow — Inner Dance

    S21–S24 first statement. ChaeWon, Sullin, SeoAh, JiYeon.

Tours & rooms she walked

  • 2026 · Asia · Asia tour

    My Secret New Zone

    First Asia tour under the msnz banner, 2026. Performance Gravity chose each unit’s songs. msnz is the OT24 umbrella that split into Moon, Sun, Neptune, and Zenith. This page is the tour note, separate from the dimension page and from ANDLESS. This archive does not sell tickets.

Same orbit