Eugène Collache Eugène Collache ( 1850s ? - ? ) was an officer of the French Navy in the 19th century . Based on the ship " Minerva " of the French Oriental Fleet , he deserted when the ship was anchored at Yokohama harbour , with his friend Henri Nicol to rally other French officers , led by Jules Brunet , who had embraced the cause of the Bakufu in the Boshin War . On November 29 , 1868 , Eugène Collache and Nicol left Yokohama on board a commercial ship , the " Sophie - Hélène " , chartered by a Swiss businessman . The two French officers first reached Samenoura Bay ( 鮫ノ浦湾 ) in the province of Nambu ( modern Miyagi Prefecture ) , where they learned that the Imperial forces had subdued the Daimyos of Northern Japan , and that the rebel forces favorable to the Shogun had fled to the island of Hokkaidō . They decided to go further north to Aomori , where they were warmly received by the Daimyo of Tsugaru . A visiting American ship brought them the news that an arrestation order against them had been issued . Eugène Collache and Nicol decided to board the American ship and reached Hokkaidō . During the winter of 1868 - 1869 , Collache was put in charge of establishing fortifications in the volcanic mountain chain protecting Hakodate ( Nicol was put in charge of organizing the Navy ) . On May 18 , the decision was taken to make a surprise attack on the Imperial Navy , which was moving north to confront them . Collache thus participated to the Naval Battle of Miyako . He was on the " Takao " , former " Aschwelotte " , which he was commanding . The two other ships were the " Kaiten " and the " Banryu " . The ships encountered bad weather , in which the " Takao " suffered from engine trouble , and the " Banryu " was separated . The " Banryu " eventually returned to Hokkaidō , without joining the battle . To create surprise , the " Kaiten " planned to enter Miyako harbour with an American flag . Unable to achieve more than three knots due to engine trouble , the " Takao " trailed behind , and the " Kaiten " first joined battle . The " Kaiten " approached the enemy ships and raised the Bakufu flag seconds before boarding the Imperial warship " Kotetsu " . The " Kotetsu " managed to repel the attack with a Gatling gun , with huge loss on the attacking side . The " Kaiten " , pursued by the Imperial fleet , steamed out of Miyako Bay just as the " Takao " was entering it . The " Kaiten " eventually escaped to Hokkaidō , but the " Takao " was unable to leave the pursuers and wrecked herself voluntarily . Trying to escape through the mountain , Collache finally surrendered after a few days together with his troops to the Japanese authorities . They were brought to Edo to be imprisoned . He was judged and condemned to death , but he was finally pardoned . He was transferred to Yokohama on board the French Navy frigate Coëtlogon , where he joined the remaining of the French rebel officers led by Jules Brunet . During his adventure , Eugène Collache wore the Japanese dress , whether on the contrary some of his Japanese military colleagues wore Western uniforms : Back in France , he was discharged from the armed forces and court - martialed as a deserter , but the sentence was light , and he was allowed to reenlist for the Franco - Prussian War together with his friend Nicol . He wrote " An Adventure in Japan 1868 - 1869 " ( " Une aventure au Japon 1868 - 1869 " ) , which was published in 1874 .