Sammai incident (also known as Kanagawa incident, also known as Richardson incident in the past) was an incident in which samurai attacked foreigners in Sammai village, Kanagawa Prefecture, Japan on September 1862. The incident led to the shelling of Kagoshima by seven British warships, which was known as the Sa-Ying War in history.

On September 1862 and 14, four Englishmen rode on the Donghai Road in Shengmai Village (now Hejian District, Yokohama City). Among them are Charles Richardson, a businessman who travels between Yokohama and Shanghai, Clark, his shop assistant, and Marshall, a British businessman who lives in Hong Kong. On the way, they met Shimadzu Jiuguang and his 700-member guard of honor. Shimadzu Jiuguang was the guardian of Samoan lords, and he conveyed to the shogunate the imperial court's will to fight against foreigners.

The guard of honor stood on the whole road. Traditionally, if civilians meet Daming's guard of honor, they have to kneel down and make way, but these four British people refused anyway, which is considered rude to Daming. At the same time, Mrs. Marshall's horse was suddenly frightened and rushed into the honor guard. Narahara of Shimadzu Guard immediately pulled out his knife and cut it at Charles. The guards who came up immediately killed him and seriously injured the other two.

Mrs Marshall was basically unhurt. Britain asked the shogunate and Samoa to punish the murderer and pay compensation. Shogunate compensation100000. But at that time, the anti-foreign movement was prevalent, and the Samoan, the perpetrator, rejected the British request.

In retaliation, the British sent a fleet to shell Kagoshima (Eagle War) the following year. Taking this as an opportunity, Samoans turned to the founding policy and approached Britain. After his death, Charles was buried in Yokohama Cemetery for Foreigners, and the sides of his grave later became the graves of Clark and Marshall.