day of the release, her fourth compilation album Good Bye Train: All Time Best 2000–2013 was released. The album was a commercial failure, only managing to peak at number sixty-eight on the Oricon Albums chart. In January 2014, Onitsuka embarked on the concert tour "Heart Beat Tour 2014", as the vocalist of the band Chihiro Onitsuka and Billy's Sandwiches. Her single "Inori ga Kotoba ni Kawaru Koro" was released in May 2014 and served as the theme song to the Japanese supernatural horror film Ju-On: The Beginning of the End. In September 2014, the debut album of Chihiro Onitsuka and Billy's Sandwiches Tricky Sisters Magic Burger was released. The follow-up single "Starlight Letter" was released in April 2015 with access exclusive for her fan club. She also wrote a song "Natsu no Tsumi" for Natsumi Hanaoka's debut single. The song helped her earn a Japan Record Awards nomination for Best New Artist. 2016–present: Syndrome and upcoming eighth studio album On January 28, 2016, Onitsuka's performance, entitled Chihiro Onitsuka "Tune Hour 2016", was broadcast live on Ustream, in the performance, she made a strong impression that she had recovered from her bad vocal condition. In April 2016, Onitsuka embarked on the concert tour Tigerlily. In November 2016, Onitsuka released her first single under Victor Entertainment, "Good Bye My Love", as the lead single from her eighth studio album. Although the song only managed to peak at number thirty-five on the Oricon Weekly Singles chart, it became her best-selling single in the previous seven years since "Kagerō". Onitsuka's eighth studio album, Syndrome was released on February 1, 2017. The album sold better than her label expected and sold out in the several CD stores. Syndrome peaked at number fifteen on the Oricon Weekly Albums chart and spent nine weeks there, selling more than 11,000 copies. To promote the album, Onitsuka embarked on the concert tour of the same title as the album from April 2017 to July 2017. In June 2017, Onitsuka released her first live album Tiny Scream, which compiled from her performance at Breeze Tower, Osaka in June 2016, and Nakano Sun Plaza, Tokyo in November 2016. The album peaked at number twenty-two on the Oricon Weekly Albums chart and topped the Onkyo High-resolution audio chart. In August 2017, Onitsuka performed at one of the biggest music festivals in Japan, Rock in Japan Festival. In June 2018, Onitsuka embarked on