REBORN! - Season 4 Episode 83 Information Divulged

When the battle is over, Hibari shows Tsuna and the others the entrance to his base which is also connected to the Vongola base. Once everyone returns to the Vongola secret base, Bianchi and Fuuta arrive to give new information on the Millefiore Family. They reveal the location of the Millefiore base on Japan which is under the Nanimori Station underground Shopping Mall. They decide they must train before beginning their attack on the Millefiore.