Hoshoku-sha

These blue sonars that are distributed to the first 400 contestants that ascend the left staircase are shown as headbands with a shining blue light in the middle of it. These contestants are hunting those with red sonars that have already acquired their specific piece of treasure. Once the red sonar carrier has their treasure in their hands, the blue sonar will react by flashing gradually letting them know that it's active. The light will flash faster and faster the closer the hunter gets to the carrier, once they apprehend the treasure the light will go on standby until it's time for them to hunt again.