Studio Apartment, Good Lighting, Angel Included. 4

Disaster strikes when Shintaro and Towa's air conditioner breaks down! But just as they're about to faint from the sweltering heat, Lilishka invites them to a summer retreat, courtesy of the Occult Research Club. Looks like the crew will be staying at a vacation home owned by Hisui's family, so why do they need to take a helicopter...?!