The Beginning of the Nightmare! - S1.E10

Tsugumi becomes upset when she receives a letter from her mother informing her that her dog, Pochi, had gotten involved in an accident, and ends up lashing out at Meme for forgetting things so easily. That night, Tsugumi and Anya follow Meme during one of her sleepwalks, winding up at the hidden research room where they are discovered by Akane and Clay.