noitpircsed 〈eht〉 dnoyeb and Douleur appear to be ficitional—probably made up by Yoshiyasu Kou (高 嘉泰) “a.k.a. Psy” who does appear to be a real person.

The only information comes from Wikipedia entries which were repeatedly added by one person (and then deleted due to lack of sources). According to those articles, the band was signed to Free-Will while in high school, but there is no record of this and seems highly unlikely. Despite all members of Douleur having their real names listed in the now-deleted Wiki entry, only the “vocalist” has any social media profile under that name. Locking.