A summary of trends in social media posts during the 2026 Yokohama mayoral election. The period covered was 4 to 18 October, including the public notice date. The total number of posts was approximately 920,000, with post volume surging shortly before the public notice date and spreading widely toward the end of the election campaign. The volume of discussion by candidate and issue was also revealed.
There were 925,861 related posts on X during the 2026 Yokohama mayoral election period, from 4 October to 18 October, approximately 4.4 times the number in the preceding week before the public notice date. Posts surged on the public notice date, reaching 43,294 per day, a 5-fold increase from the previous day.
Original posts peaked on the day of voting and ballot counting, with 6,910 on 18 October and 85,331 the following day, as posts commenting on reports of the results and the elected candidate appeared one after another.
By candidate, Fukuyama Atsushi (福山あつし) attracted the most attention, with 296,520 posts, followed by Harasawa Atsumi (原沢あつみ) with 178,864 and Yamamoto Riken (山本理顕) with 172,216. Posts about Fukuyama increased particularly sharply after the public notice date, reaching a peak around 16 October toward the end of the campaign.
By issue, harassment ranked first with 63,490 posts, followed by subsidies for Korean schools with 31,423 and school lunches with 21,992. Discussions concerning urban development and integrated resorts continued to focus on IR, with references also made to the Garden Expo and plans for Yamashita Pier.
Overall, social media functioned as a forum for comparing candidates and policies, while it was pointed out that verifying the accuracy and sources of information is important.