Kaztano
カズターノ
Kaztano is person that is important to Togusa as he was the one who got him first place tickets to his favorite Idol Ruri Hijiribe, which were quite hard to obtain. It is believed that Kaztano is an Italian foreigner.
While he is an active minor character in the anime, Kaztano does not personally appear in the novels (his name was mentioned though).