相対性理論 (Sotaisei Riron) Are An Indie-pop Group That Formed In Tokyo In 2006. The Members Are やくしまるえつこ

相対性理論 (Sotaisei Riron) are an indie-pop group that formed in Tokyo in 2006. The members are やくしまるえつこ (Etsuko Yakushimaru) (vocals), 真部脩 (Shuichi Manabe) (bass), 永井聖 (Seiichi Nagai) (guitar), and 西浦謙助 (Kensuke Nishiura) (drums) who also works as a support drummer for the rock group MASS OF THE FERMENTING DREGS. 

相対性理論, also known as Theory of Relativity are known for being very private about their personal lives; it is rumored that taking live photos is strictly forbidden and media coverage has always been minimal. They have rejected various TV appearances, photo and press opportunities and also interviews simply because they do not follow the path of advertising themselves.

The debut EP シフォン主義 (Chiffon Shugi) was released in 2008 under the indie label Mirai records and won the 1st all Japan CD shop award shortly after. Since then they’ve released 3 amazing full length albums and reached single digits on the Oricon charts for the album Hi-Fi Shinsho.

This is LOVEずっきゅん from the EP シフォン主義.