Smackgirl was a Japanese mixed martial arts promotion focused solely on female fighters. The promotion also held grappling and amateur events along with its main line of professional MMA cards. After financial difficulties throughout 2008 the promotion was sold to Marverous Japan Co.,Ltd. and rebrandedJEWELS.
Unlike conventional MMA in Japan, Smackgirl did not allow striking to the head while in a grounded position. There was also a 30-second limit for ground fighting  but it was abolished by 2008. There were four weight classes: flyweight (under 48 kg), lightweight (under 52 kg), middleweight (under 58 kg), and openweight (no limit).
Before being Smackgirl, the ReMix banner was used and held its first event in December 5, 2000 (2000-12-05). After another event with the ReMix brand, the promotion morphed into Smackgirl in May 2001 (2001-05).