Sigma (album)
album by REOL (group)
Sigma (stylized with the Greek symbol Σ) is the only studio album by Japanese musical unit REOL. It was released on October 19, 2016 by Toy's Factory in two physical editions—a standard CD, and a CD and DVD bundle—and for digital consumption. Prior to their formation, each member—Reol, Giga and Okiku—worked with each other on numerous musical projects until finalizing a record contract with Toy's Factory in early 2016. The material on the album were written, sung and co-composed by Reol, while production was handled by all three artists and arranged by Giga.
Sigma is an electronic dance album that incorporates elements of hip-hop, contemporary pop and club sounds. Lyrically, the record delves into enjoyment, love, having fun and a variety of expressions, all encased by their current state of mind, as described by them as "transitory". Upon its release, Sigma received positive reviews from music critics. Several commentators complimented the group's musical direction, alongside Reol's vocals and commercial appeal.
Commercially, Sigma experienced moderate success in Japan, reaching the top ten on both the Oricon Albums Chart and Japan Hot Albums chart, the latter hosted by Billboard. In order to promote the album, the album tracks: "ChiruChiru", "Give Me a Break Stop Now", and "YoiYoi Kokon" were served as digital singles, accompanied with additional music videos co-created by Okiku. Furthermore, REOL had appeared on several promotional formats such as live performances, magazines and interviews on social media.
This brief starts where responsible research should: with the source description of “Sigma (album)” as album by REOL (group). Everything that follows is an evidence route, not borrowed authority.
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The subject matters to the arts & letters register because the source frames it as album by REOL (group). Its deeper value depends on whether names, dates, institutions and citations support that framing.
Reception evidence should be dated and situated: later canonical status may differ sharply from the work’s initial circulation. The source revision retrieved here is dated Jun 15, 2026. The linked authority identifier is Q27941783. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 2016.
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This entry incorporates text from “Sigma (album)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.