She began training in rhythmic gymnastics at age three in the school of Hiroko Yamasaki, who represented Japan in the sport at the 1984 Olympics.
[1][2] Hanai remained in rhythmic gymnastics and participated in a number of tournaments including the All Japan Championship series in 2007 and 2008, until she was twenty-one, when a serious injury forced her to retire.
[4][5] In 2011, she entered the Kobe Collection "One Life Model Audition" where she won the Special Jury Prize, cheered on by her teammates from the "ZENT Sweeties".
[9] Hanai's second featured movie role was also with director Shusuke Kaneko, starring as Arisa in the science fiction action film Danger Dolls, released theatrically in Japan in September 2014.
[10] Also in late 2014, she was a cast member in the Edo period TV costume drama Osoroshi (おそろし～三島屋変調百物語) broadcast as a miniseries on NHK from August to September 2014.