On the morning of the 16th, two boats capsized near Henoko, Okinawa, where the relocation of a US military base is ongoing. Among the passengers, four were injured, and two, identified as 71-year-old captain Hajime Kanai and 17-year-old high school student Tomoka Takeishi from Kyoto, passed away after being hospitalized. The area was under a high wave warning indicating rough sea conditions at the time of the incident. The coast guard suggested that the vessels were overturned due to large waves.

The students, part of a group of 270 from Doshisha International High School, were participating in a peace study program and had split into two protest boats. Teachers did not join the excursion. This tragic occurrence marks the first time a fatal incident has been reported in connection to the protests against base relocation, which have been ongoing for over 20 years. The Japanese and US governments are pushing for the relocation to Henoko due to persistent complaints regarding the Futenma airbase in Southern Okinawa, planning to complete the construction by the mid-2030s.

However, many local residents oppose the relocation and demand the base be moved outside Okinawa. The tensions continue to rise, highlighted by a protest the prior day in Naha, where approximately 60 residents expressed their fears regarding Okinawa being drawn into war, opposing the deployment of US troops to the Middle East. They carried banners stating their opposition to the US military's involvement, emphasizing their unwillingness to allow Okinawa to serve as a base for attacks against Iran, and calling for peace and the withdrawal of troops.