At the very beginning of the movie (where "My Generation" by "The Who" plays), when Shoya and his friends enter his mother's hairdresser salon, Nishimiya with long hair can be seen looking at a magazine about hairstyles in the salon. The next day when Nishimiya starts to Shoya's school, she has short, bob-cut hair.
The opening song is "My Generation" by The Who. Naoko Yamada's previous work, K-On! (2009) and it's film companion K-On! The Movie (2011) also paid tribute to the famous British band.
During the time when Shoko confessed her feelings to Shoya, Shoya misinterpreted her saying "suki" (like/love) as "tsuki" (moon) because both words sounded very similar (matching pronunciation), along with his lack of emotional understanding and density. However, either intentional or accidental, the phrase "the moon is beautiful" that Shoya expressed to Shoko after misinterpreting her words can be used as flirting given proper context. They are both unaware that they are actually flirting with each other.
Based on the manga of the same name by Yoshitoki Oima. The series was originally published as a one-shot in Kodansha's Bessatsu Shonen Magazine and was later serialized in Weekly Shonen Magazine from August 2013 to November 2014. Its chapters were collected in seven tankobon volumes.