However , on April 18 , 1845 , an emissary from the shogunate gave the ship permission to proceed .
The Japanese normally wanted to avoid contact with outsiders due to the Tokugawa shogunate 's official policy of national isolation .
On April 18 , 1845 , an emissary from the shogunate gave the ship permission to proceed .
The Japanese normally wanted to avoid contact with outsiders due to the Tokugawa shogunate 's official policy of national isolation .