Halloween is getting popular and popular in Japan. Yokosuka area has also Halloween festival, costume contests and so on.
This coming Saturday 25th, different venue has different festival. Closest location is Dobuita-street and Yokosuka Chuo station area.
Actual Halloween is on October 31st, of course and this year is Friday! If you have time, Roppongi in Tokyo would be one craziest place to hang out and worth to check it out.