Sprinting, Late Summer in Backwater - S1.E6

Koharu (Sei Shiraishi) heard from a health teacher, Moriyama (Masanari Wada), that there is a warehouse behind a mysterious antique shop. After consulting with Akiho (Natsuki Deguchi), she secretly infiltrates Natsuna (Momoka Ito), who is preparing for the national athletics competition. The two of them sneaked into the store, but as expected, the store manager (Gaku Hamada) found out, and the homeroom teacher Hoshimiya (Aya Asahina) also reported and apologized. The two thought that the secret of the Girl Gun Lady was in the warehouse, and suggested to Natsuna, "Let's break into the Girl Gun Fight." Then, I talk to Alice (Yuno Ohara) in a parallel world, but I can't find a way to open the "bilibili wall" that surrounds the school ... On the other hand, Matsuko (Anna Ishii) is not the commander Bianca (Rio Teramoto) of Bravo Tango, but for some reason Alice offers a consultation- !?