She was in the talent agency Link-Plan along with Aguri Onishi before she moved to DigitalDouble in October 2020.She is considered to be the best at SIF among the Nijigasaki High School Idol Club seiyuus.During Love Live! AbemaTV SIF ALL STARS Special, she said she really likes Kotori.Mayu's surname Sagara means "phase, aspect, countenance, mutually, fellow" (相) ( saga) and "good, virtuous, respectable" (良) ( ra).
The name Mayu means "jasmine" (茉) ( ma) and "excellence, superiority, gentleness" (優) ( yu).She also has a Level 5 Certification for mental arithmetic and a driver's license. Her skills are Soroban, darts, and tenor saxophone. Her hobbies include karaoke and searching for delicious restaurants. On August 2, 2022, Mayu tested positive for COVID-19. She is also a member of seiyuu unit Prima Porta alongside other Nijigasaki cast members Shu Uchida and (formerly) Aguri Onishi. Some of the characters she voices are Miruki Amauri in Waccha PriMagi!, Ume Toranomon in Aru Asa Dummy Head Mic ni Natteita Ore-kun no Jinsei, Miku in Idol Memories, and Ayaka Mizusawa in Pride of Orange.