Arimachi was born in Sakai on July 12, 1988. After graduating from Fukui University of Technology Fukui High School, she joined Ohara Gakuen JaSRA in 2007. In 2008, she moved to Okayama Yunogo Belle. She played 132 matches and scored 32 goals for the club. In 2015, she moved to Vegalta Sendai (later "Mynavi Vegalta Sendai"). She retired end of 2020 season.