Wikidata records 4 members of BtoB Blue. 4 of them have a birth date on record, born between 1990 and 1995. The ages below are as of 2026 — the birth dates are not.
This is a small line-up on record — 4 people, so every row below is a meaningful share of the group and one missing birth date changes the picture. Every one of them has a birth date, so nothing in the age table is estimated. The birth years run 1990–1995, 5 years apart. 2 of them share the same star sign (Pisces). Wikidata gives a birthplace for 4 of them, across 3 different places.
Ages are as of 2026; birth dates do not move. These are the members Wikidata records, not the current line-up — people who have since left are included and we cannot tell the two apart.
Seo Eun-kwang, born 22 November 1990 — 36 in 2026. The youngest is Yook Sung-jae, born 2 May 1995, 31 in 2026. That is a gap of 5 years.
| Name | Born | Age in 2026 | Star sign | Shares the date with | Born in | Wikipedia languages |
|---|---|---|---|---|---|---|
| Seo Eun-kwang | 22 November, 1990 | 36 | Sagittarius | nobody else | Yongin | 14 |
| Lee Chang-sub | 26 February, 1991 | 35 | Pisces | 1 other | Suwon | 14 |
| Lim Hyun-sik | 7 March, 1992 | 34 | Pisces | nobody else | Seoul | 15 |
| Yook Sung-jae | 2 May, 1995 | 31 | Taurus | 4 others | Yongin | 23 |
A dash means we hold no figure, not a zero.
The sign column is arithmetic on a birth date and nothing else. We do not say what any of it means, because we have not measured anything that would let us say it.
We did test the nearest thing to a claim. Across 1,047 Korean actors who reached a Netflix chart, the spread across birth-year animals was indistinguishable from chance. That test is here, with the working shown. Sign boundaries also move by a few hours from year to year, so someone born on a boundary day may fall the other way in their own birth year.
Wikipedia language count is not a measure of how good someone is. It measures how widely they are written about, and it favours people who have been famous longer.
We do not publish heights. Wikidata records a height for about 3% of the Korean performers we hold, and a figure built on 3% would be wrong far more often than right.
We hold 428 Korean groups in all. 165 of them have fewer than 3 members we could name, and we do not publish a page for those — they are counted, not hidden.
Wikidata records 4. This is not the current line-up — the field holds everyone recorded as part of the group, including people who have left.
They were born between 1990 and 1995. The full list of dates is in the table above. Birth dates do not move; ages do — the ages here are as of 2026.
We cannot tell you. Wikidata records a height for about 3% of the Korean performers we hold. We would rather say we do not know than publish a figure that would be wrong far more often than right.
Wikidata, read by item number: group membership (P527), date of birth (P569), place of birth (P19). CC0. Nothing here is copied from a fan wiki or a news write-up.