Aku no Hana EP13 - Flowers of Evil 13 of 13

Kasuga enters Nakamura's room. He finds her diary and starts reading it. He recalls what had happened. Nakamura comes back, seizes the diary and runs away. He follows her and catches up to her. This time, he asks her to make a contract with him: they'll do what they can in order to leave for good someday.