The title 5 Centimeters Per Second comes from the speed at which cherry blossoms petals fall, petals being a metaphorical representation of humans, reminiscent of the slowness of life and how people often start together but slowly drift into their separate ways
4 team members of the team were so inspired by the movie and story that they decided to marry their partners during production of this movie, according to the director.
Makoto Shinkai had expressed that, unlike his past works, there would be no fantasy or science fiction elements in this film. Instead, the feature film would attempt to present the real world from a different perspective. Makoto's film gives a realistic view of the struggles many face against, time, space, people, and love.
In 2009 a Chinese animation company Liuzhou Lan Hai technologies Ltd. admitted to plagiarizing several backgrounds from the film to use in their own animation series.
Originally, the director planned to make 10 short stories of 5 mins, each with their own song. Eventually, he cut this down to only 3 stories. The song he picked was picked because he likes it personally and because he felt it perfectly suits the story.