Nagano was born on in Gifu, Gifu, Japan. She started wrestling in the fourth grade of elementary school and continued wrestling in middle school and high school, becoming second place in all of Japan at the high school level. While studying at Chukyo Women's University, she was an amateur wrestling champion and finished fourth in the 55 kg division of the 2002 Japan Queen's Cup; the same tournament where future Olympic medalist Saori Yoshida finished first. In 2004, she was ranked fourth in the 51 kg class, but left the university after three years before graduating and stopping wrestling. Nagano moved to Tokyo in 2005, where she joined a modeling agency of independent wrestling and started talent activities. She was eventually charmed by MMA when she visited S-KEEP.
Nagano debuted in MMA in an exhibition match against Megumi Yabushita at Smackgirl: F 2006 on. She made her professional debut against Megumi Fujii and lost via submission at Smackgirl: Starting Over at Korakuen Hall on. After winning her next fight by split decision and losing her third by decision, she went on to win her following three fights by submission. In the process, she won the 2009 Rough Stone Grand Prix 54 kg & under tournament after defeating Yoko Kagoshima in the tournament final. Following a unanimous decision win and going on a five-fight winning streak, Nagano was upset at Jewels 8th Ring on by Norwegian fighter Celine Haga, who was an underdog after losing her first four professional fights. Haga dominated the whole fight, earning a unanimous decision win. The loss was so devastating that Nagano was in tears even before the fight ended. Nagano managed to avenge this loss in the Jewels Lightweight Queen Tournament Opening Round by defeating Haga with an armbar submission at Jewels 9th Ring on. She faced Seo Hee Ham in the tournament semi-finals on at Jewels 11th Ring and was defeated by split decision after two rounds. Nagano was scheduled to face Emi Murata at Jewels 12th Ring on in Tokyo, Japan, but the event was cancelled after the Tōhoku earthquake and tsunami earlier in the day. She then faced Murata at Jewels 14th Ring on and defeated Murata by submission in the first round. Nagano rematched Megumi Fujii at Jewels 15th Ring on. She was defeated by unanimous decision. Nagano faced Mei Yamaguchi at Jewels 17th Ring on. She was defeated by split decision. Nagano then faced Emi Fujino at Jewels 18th Ring on. She lost the fight by unanimous decision. On, Nagano faced Anna Saito at Jewels 19th Ring in Osaka, Japan. She won the fight by submission due to an armbar in the first round. Nagano's next fight took place on when she faced Tomo Maesawa at Jewels 21st Ring. She defeated Maesawa by technical submission due to an armbar in the second round. On, Nagano competed outside Japan for the first time when she faced Alexandra Chambers at Brace For War 17 in Australia. She was defeated by TKO early in the first round. Nagano faced Rina Tomita for a third time at Jewels 22nd Ring on. The fight was Tomita's retirement match. Nagano defeated Tomita by submission due to an armbar in the first round. Nagano next faced Emi Tomimatsu at Jewels 23rd Ring on. She won the fight by unanimous decision. On, Nagano faced Takumi Umehara at Jewels 24th Ring. She defeated Umehara by submission due to a rear-naked choke in the first round. Nagano next faced Akiko Naito in Naito's retirement fight at Deep Jewels 1 on. She defeated Naito by submission due to an armbar in the first round. In a rematch at Deep Jewels 2 on, Nagano faced Emi Tomimatsu in the opening round of the Deep Jewels lightweight title tournament. She was defeated by unanimous decision. On December 28, 2013, Nagano announced that she was retiring from MMA the following February. However, on February 6, Nagano announced she was pregnant and would have to pull out of her exhibition match with Saori Ishioka. Nagano's retirement ceremony took place on February 16 at Deep Jewels 3.
Nagano made her professional wrestling debut on with wrestling promotion Ice Ribbon. After competing in Ice Ribbon for a few months, it appeared that she was no longer with the promotion as of ; apparently focusing more on her MMA career after being pushed as a top star in Jewels. In January 2011, Nagano returned to professional wrestling, competing for the new WorldWonder Ring Stardom promotion. She worked the promotion's first ever show on January 23, 2011, during which she defeated Eri Susa. However, after only a handful of appearances, which included her losing to Yoko Bito in a World of Stardom Championship tournament semifinal match on July 24, 2011, Nagano once again went inactive to concentrate on her career with Jewels. On April 2, 2013, Stardom announced that Nagano would be returning to take part in the promotion's big Ryōgoku Kokugikan event on April 29. In her return match at Ryōgoku Cinderella, Nagano teamed with Nanae Takahashi and Tsukasa Fujimoto in a six-woman tag team match, where they defeated Hiroyo Matsumoto, Kaori Yoneyama and Syuri.
