Sea of Shadows

The Sea of Shadows was a region no sane man dared to venture. The seas of Rokugan were hazardous at the best of times; when combined with the foul touch of the Shadowlands they became an area of unimaginable danger. A man who fell overboard in a storm was almost certainly dead, or may as well be. The storms that blew over the black waves possessed a malevolent hunger. Creatures beyond description skulked beneath the water, constantly seeking living prey to torment and consume. Even the Mantis Clan, who claimed greater mastery of the sea than any other clan, did not challenge the Seas of Shadow.

The Osaku Route is a current of uncorrupted ocean cutting through the Sea of Shadows. The route is controlled by the Crab Clan by order of the Emerald Champion. It is believed to have been created by Osano-Wo to protect a shrine that his son, Hida Kenzan erected in grief over his father's death. The shrine was home to the Tetsubo of Thunder until 1167, when it was removed by Yoritomo Rui and given to the Bat Clan. After Rui's visit it seemed that Osano-Wo began to widen the route in approval.