Matsushita would arrive at the Miura Peninsula on Friday nights, stay at a training camp, and spend weekends practicing sailing in
Sagami Bay. She spent her days immersed in
yacht racing, but she changed her mind and took the company's internal exam to switch to a general position. She was in charge of human resources in the general affairs department. During her tenure there, she became interested in social security issues, and enrolled in a correspondence course at
Keio University. She left the company in 2001. In 2004, she completed a master's degree in applied economics at the Graduate School of Economics at
Waseda University. In the
20th Tokyo Metropolitan Assembly election in June 2017, she ran in the Musashino City constituency as a candidate endorsed by the
Democratic Party. She received endorsements and support from the
Tokyo Seikatsusha Network, the
Liberal Party, and the
Green Party Greens Japan, but was defeated by a newcomer,
Kunikazu Suzuki, endorsed by the
Tomin First no Kai, by about 5,000 votes.
Mayor of Musashino City On August 14 of the same year, Musashino City Mayor
Morimasa Okami announced his intention to retire and not run in the 2019 mayoral election. At the "Basic Autonomy Ordinance Symposium" held on November 3, 2022, it was stated that according to Article 19 of the Musashino City Basic Autonomy Ordinance, the establishment of necessary matters will be determined by separate ordinance, and that the opinions of citizens and the assembly will be sought in the future. Following her nomination as successor to
Naoto Kan, who indicated he would not run in the upcoming general election for the House of Representatives, Matsushita announced her intention to run as a candidate endorsed by the Constitutional Democratic Party in Tokyo's 18th district. Kan stated that he was "adjusting the timing of his resignation so as not to affect city administration", but stated that he would submit his resignation notice on the 10th of the same month, with an effective date of the 30th of the same month. His acting position will be filled by Deputy Mayor
Hideho Ito. In the mayoral election held on December 24 of the same year to elect a successor, he fielded former Musashino City Council member
Yuko Sasaoka as his successor candidate, but she lost to
Yasuhiro Omino, also a former Musashino City Council member who was endorsed by the LDP and
Komeito Party. This marked the first shift to conservative city administration since
Masatada Tsuchiya retired in 2005.
Member of the House of Representatives Four candidates ran in the
50th general election for the House of Representatives on October 27, 2024, in the New Tokyo 18th District (Musashino City,
Koganei City,
Nishitokyo City): Matsushita,
Kaoru Fukuda of the LDP,
Yukiko Tokunaga of the
Sanseitō Party, and
Ryo Higuchi of the
Japanese Communist Party. Fukuda defeated Matsushita by approximately 2,200 votes and won his first election. The Constitutional Democratic Party won five seats in the Tokyo proportional representation block. Matsushita, who had the second-lowest defeat rate (97.796%), won her first election through proportional representation. == Political positions ==