Machico is the stage name of Machiko Saitō, a Japanese singer and voice actress born on March 25, 1992, in Kure, Hiroshima Prefecture. Her interest in the industry was sparked by voice actor Yuji Mitsuya and after visiting a voice actor training school. In 2011, she became a finalist in the 36th Horipro Talent Scout Caravan, a next-generation voice actor audition. Although she did not win the grand prize, this led to her debut with the agency Horipro International. Her professional debut came in 2012 when she performed the theme song "Magical Happy Show!" for the PC game Supipara - Alice the magical conductor.

Machico's career as a voice actor began in 2013 with her casting as Ibuki Tsubasa in the mobile game The Idolmaster Million Live!. This role became one of her most significant and longstanding, continuing through subsequent games and the 2023 anime adaptation. Her first regular role in a television anime was as Sophia Mertesacker in World Break: Aria of Curse for a Holy Swordsman in 2015.

She has since portrayed a wide variety of characters. Among her most prominent roles are Tokai Teio in the multimedia franchise Uma Musume Pretty Derby, appearing in the second season of the anime and related OVAs; Ithea Myse Valgulious in WorldEnd; Hikari Kokura in Chidori RSC (Rifle Is Beautiful); Kurea Ōba in Iwa-Kakeru! -Sport Climbing Girls-; Nene Kusanagi in the COLORFUL STAGE! (Project Sekai) game and film; and Hikaru Fuwa in Idol Bu Show. Her filmography also includes roles in series such as The Ryuo's Work Is Never Done!, Three Leaves, Three Colors, and the Pretty Cure franchise.

Concurrently with her voice acting, Machico has maintained an active career as a singer. She has released multiple albums, including COLORS in 2014 and COLORS II -RML- in 2015, which featured her first attempt at writing lyrics. She has performed numerous theme songs for anime, including the opening themes for both seasons of KonoSuba and The Ryuo's Work Is Never Done!, as well as opening and ending themes for several Pretty Cure series. In 2019, she became a member of the official voice actor unit Rifling 4, formed for the anime Rifle Is Beautiful.

Throughout her career, Machico has been part of recurring collaborations. She was a regular participant in the Anisong Ichiban!! concerts with fellow voice actors from her generation at Horipro. She is known for her close friendships with fellow The Idolmaster Million Live! cast members Haruka Yamazaki, Aimi, and Minami Takahashi.

In late 2022, Machico tested positive for COVID-19 and, shortly after recovering, announced her departure from Horipro International on November 30 after a decade with the agency. She joined the agency Style Cube the following day, on December 1, 2022. Her music is released under the Nippon Columbia label. In recognition of her roots, she was appointed as a Kure Tourism Ambassador in 2021 and has also served as a PR ambassador for agricultural cooperatives in Hiroshima, a nod to her background helping on her grandparents' farm.