Kono Yo no Hate de Koi wo Utau Shoujo YU-NO: Mugen no Heiretsu Sekai

この世の果てで恋を唄う少女YU-NO「無限の並列世界」

Episode 26.5, reward for reaching at least 1000 sales for the first Blu-ray volume. The episodes shows different possible outcomes for the protagonist.