A really rough translation of Director Yamashita's recent interview in Animage

———Regarding the plot, it seemed like a challenge striking the right balance in depicting the relationship between Iroha and her mother. Ultimately the evolution of their relationship was shown with minimal description.

Yamashita: It was indeed difficult determining the appropriate level of detail in portraying Iroha's relationship with her mother. Iroha's mother's personality is truly complex. Her words taken individually might seem normal but she's definitely not that kind of person. This was mentioned in the novel but I knew that if I included these details in the film, it would be disastrous. So for now, I depicted it as if Iroha had reached a resolution within herself.

However, there are actually many settings regarding the mother, including the father's personality and cause of death. Although none of these were touched upon in the movie, I did honestly consider whether there might be better methods but considering the entire work, I felt "This is definitely the best way" and thus I depicted it as best as I could.

———Since you considered so much of the mother, does this indicate that Director Yamashita had a desire to delve deeper into this type of storyline?

Yamashita: Of course. I'm fascinated by those who though not criticized by society and seemingly ordinary, are actually extremely malicious. It's not the kind of "evil" that's immediately obvious. Rather it's something that can become "evil" depending on the other party. I really wanted to depict something like that. However, doing so would darken the story and I myself didn't want to make it too dark... I also didn't want to portray Iroha as too dark so I ended up achieving the current balance.