Shimada joined AKB48 in 2009. In April 2017, Shimada announced that she would graduate from the group in September 2017 and retire from the entertainment industry. Her graduation live concert was held on November 13, and she released her photo book the same month. She posted her farewell message on her official
Twitter and
Instagram accounts on December 31, 2017 and stated that she will only maintain her Instagram account going forward. In 2018, Shimada moved to
London and lived there for about a year to learn English. She worked at an advertising agency after returning to Japan, and went on to establish the company Dct Inc. in May 2021. Drawing from her own experiences, the company offers courses to prepare
Japanese idols for the general workforce should they decide to retire from the entertainment industry, considering that they often start out while in school and have little or no work experience outside the industry such as
part-time work, although they might have an advantage in communication skills. She later established a second company named Clover Academy, which offers a combined course of performing arts training and
child care qualification for high school graduates who aspire to enter show business, similarly to provide an option for a second career should they later retire. Shimada also helps manage her family's
ryokan, Tachibana, in her hometown of
Atami. After the
2021 Atami landslide, she launched a crowdfunding project for reconstruction of the affected areas, which managed to collect 3,331,000 yen. == Personal life ==