Original: The following year, at the Convention of Kanagawa on March 31, 1854, Perry returned with seven ships and requested that the Shogun sign the "Treaty of Peace and Amity," establishing formal diplomatic relations between Japan and the United States.
Simplified: Next year, on 31st March 1854, Perry came with seven ships, and Japanese signed a treaty (known as the Convention of Kanagawa) established diplomatic relationship with the USA.