Sadie was founded by Mao, Tsurugi, Aki, Mizuki and Sora in February 2005, and comes from the English word "sad", according to vocalist, Mao. Sora departed in January 2006 for "artistic differences", and in March, Kei joined the band to replace Sora.Their first live appearance was on March 18, 2005 at Osaka Big Cat, when they were the opening act for D, Fatima, Doremidan, shulla, Kra and others.On July 27, 2005 Sadie released their first maxi single, "Kokui no Shita no Yokubou to, Kunou no Hate ni Mita Hyakkei no Yuritachi", limited to 2000 copies that sold out rapidly.On December 3, Sadie had their first oneman called "Dekiai ~ As a Sad Matter of Fact ~" in the Osaka Muse Hall in front of 250 people, introducing their new single "Dekiai", which came out a few days later and the single "Oboreru Sakana", exclusive for visitors of their concert.After Sora left the group in January, Sadie were featured on an Omnibus compilation CD called sawayaka sankumi
with the song "meisai". This CD was limited to 777 copies and came with only 3 tracks, one by Sadie, one by Billy and one by The Pumpkin Head.In March, shortly after the announcement of their first EP "The Trend Killer", Kei replaced Sora as the group's drummer.On April 19 and 26, Sadie were guests at Shoji Noriko's internet TV show shigoto mo rock mo hard ga saikou!!
.At Sadie's oneman on May 6, three days after the release of "The Trend Killer", the visitors got the chance to receive the second unofficial single "sayonara no hate".In the following period, Sadie continued to release new material; two more EPs, two more singles and also two live DVDs.In June 2008, Sadie's first studio album was released, Undead 13+2
. It contained re-recordings of old, unobtainable Sadie songs. A DVD with music videos came with the limited edition. It was also announced that another single will be released in July, named "Grieving the Dead Soul".In 2009, Sadie went on a three-man tour with heidi. and lynch.. In February 2009, Sadie released their 5th and first full length album Master of Romance
; containing 4 songs previous recorded within the following year.In July, they were invited to AM² Convention at Anaheim, California along with heidi. on July 1–3, 2011.They covered hide's song "Pink Spider" for the Tribute II -Visual Spirits-
tribute album, released on July 3, 2013.