| X21 | |
| Origin: | Japan |
| Genre: | J-pop |
| Years Active: | 2013–2018 |
| Label: | Avex Trax (since 19 March 2014), Oscar Promotion (2nd X21) |
was a Japanese girl idol group.[1] It was formed in 2013 of 21 finalists (with the average age of 14 years) of the 13th Japan Bishōjo Contest and is affiliated to the entertainment company Oscar Promotion.[2]
| No. | Title | Album details | Peaks | ||
|---|---|---|---|---|---|
| JPN [4] | JPN Hot. [5] | ||||
| 1 |
| 21 | — | ||
| 2 | Beautiful X |
| 20 | 40 | |
| "—" denotes items which failed to chart. | |||||
| No. | Title | Release date | Peaks | Album | ||
|---|---|---|---|---|---|---|
| JPN [6] | JPN Hot. | |||||
| 1 | 15 | 100 | Shōjo X | |||
| 2 | 9 | — | ||||
| 3 | 11 | — | ||||
| 4 | 21 | — | ||||
| 5 | 5 | — | Beautiful X | |||
| 6 | 10 | — | ||||
| 7 | 10 | 54 | ||||
| 8 | 15 | 30 | ||||
| 9 | 12 | 42 | ||||
| 10 | 6 | 30 | rowspan="3" | |||
| 11 | Friday Night Party | 9 | 29 | |||
| 12 | Destiny | 8 | — | |||
| "—" denotes items which failed to chart. | ||||||
| Year | Title |
|---|---|
| 2014 | "Asu e no Sotsugyō"] (YouTube Special MV) |
| "Gwiyomi Song" (キヨミ・ソング) | |
| "Koisuru Natsu!" | |
| "Happy Appli" | |
| "Xギフト" | |
| 2015 | "Shōjo X" |
| "YOU-kI no Parade" | |
| "Magical☆Kiss" | |
| 2016 | "Yakusoku no Oka" |
| "Natsu dayo! | " |
| "Kagami no Naka no Parallel Girl" | |
| 2017 | "Beautiful X" |
| "Genjitsu kara Nigeru kara Genjitsu ga Tsurainda |