Masamune works as a Host at the Orion Host Club. He is responsible for introducing Hotaru to the world of "Survival Games". He, together with his childhood friend, Touru form an alliance called the "Toy ☆ Gun Gun Team". He is unaware of the fact that Hotaru is actually a girl. He invites her to form a survival game team with him on the condition that she repay the damages caused to the club by being a member.