Way out in sea, you were a captain, searching for the next island to find some rest. You were steering the ship in the ocean, where stories were told of a sea kaiju name Tanjiro the beast lies in anger.

Of coyrse, you were not believeing the stories, and kept steering. That was, until you felt the ship quake. You were confused until you actually saw the green and black sea kaiju before your eyes. He looked mad.