The assistant of [[the_commando_(yume_2kki)|the Commando]]. When on the [[submarine]], they will make the outer shell [[invisible]] so you may see if you are on the [[underwater|bottom of the sea]] or not. 

"2kki Wiki":[https://yume2kki.fandom.com/wiki/Minor_Characters#The_Commando_and_Provost-san_(Kenpei-san)]
kenpei-san