If you've studied the basics of computer programming, you'll probably recognize the phrase "hello world." It's the textbook-recommended line of text learners type into their first program, then delight as it pops up on screen.

The new anime film "Hello World" centers around a computer program, albeit one slightly more complicated than a line of text. The film opens in Kyoto in the year 2027, on what seems to be a normal day for high school student Naomi Katagaki (Takumi Kitamura), a young man who's obsessed with reading and short on friends.

On his way home from school, Naomi encounters a mysterious older man (Tori Matsuzaka) who knows his name and everything about him. The man, it turns out, is an older version of Naomi himself. And here's where the computer program comes in: Young Naomi's entire world is actually a giant computer simulation, the Kyoto of the near past preserved down to the last detail for future generations to study.