Nikaidou plays the lead character Wakagusa Haruna, a senior high school student while Yoshizawa plays Yamada Ichiro who attends the same school as Haruna and is bullied by her ex-boyfriend Kannonzaki for being a gay. After saving Ichiro from the bullying, he reveals to Haruna that he and Yoshikawa Kozue, Haruna's junior, a student model suffering from eating disorders, had discovered a dead body on the river bed. At the same time, Haruna's friend Rumi is pregnant but doesn't know who the father is while Yamada's friend Tajima Kanna is in love with him even though he doesn't feel the same way. Just then, another dead body appears.
Nikaidou revealed that she had read the manga when she was in her teens and was impressed with the emptiness, naivety and violence exhibited in the story. As for her character, although she finds it difficult to identify with Haruna, she will try to imagine Haruna as a girl who has both strong and weak sides and imagine how she views things from her perspective. On the other hand, Yoshizawa described Ichiro as someone who doesn't feel like he is living and seems more content with relying on the presence of the dead body to justify his existence which he can sort of understand.
Sources: Yomiuri Hochi / Sponichi / Eiga.com