Several tough-looking samurai are guarding the gates. Each seki has a permanent contingent of guards who live here and guard the roads into and out of Edo. Their job is to make sure that nobody tries to sneak past without going through the check point. In addition to the guards at the gate, there are patrols that scour the coutryside looking for suspicious characters who look like they might be trying to avoid passing through the seki
There are permanent guard stations at the seki at Hakone, Kawasaki, Otsuki, Senju and a few other other key locations on the main roads to Edo. In addition, there is also a group of "military police" that helps to guard the western approaches to Edo. This group is known as the Hachioji Sennin (the thousand men of Hachioji). They got this name because their headquarters is located in Hachioji -- a key town on the Koshu-kaido. From here, they can patrol the hills that form the geographical boundary between western and eastern Japan.
This elite unit of samurai was appointed from among Tokugawa Ieyasu's most trusted troops, shortly after he moved to Edo. Today, membership in the Hachioji Sennin has become hereditary, and the members take great pride in their military skill and their responsibility for guarding the Shogun's capital against invaders and troublemakers