Choshi is a small city located on the easternmost tip of Chiba prefecture, about 2-3 hours from Tokyo by local train. It is known for its fishing ports and the Inubosaki Lighthouse.
From Tokyo, visitors can take either the JR local or rapid trains bound for Chiba. So that would most likely be the Sobu Main Line. From Chiba Station, the JR Narita or Sotobo lines can take taken to get to Choshi.
As the city is known for its fishing ports, dishes featuring the freshest catch of the day are a must-try. Also, better not forget to buy some nure-sembei as souvenirs before heading home.