Why can Light Yagami's first name be read as 'Moon'?

Open a Japanese edition and the hero's name is printed Yagami Raito, with the characters 夜神月 and a small phonetic gloss beside them. Take the characters at face value and they say something else entirely. The family name is night (夜） plus god (神）: Yagami, the night god. The given name is a single character, 月, whose ordinary readings are tsuki and getsu, and whose meaning is moon. By the book, the hero of Death Note is named Moon. The gloss beside the character overrules the book: this moon is read Raito, the Japanese rendering of the English word Light.

Japanese has a name for this: a kira kira name, a sparkling name, in which parents assign a character a reading it does not normally carry. Ohba has noted the coincidence of the term with pleasure: Light's name is, literally, a kira name. The family name, by contrast, was not the writer's deep design: Ohba has said the editor suggested Yagami, and that Ohba was not too concerned about its meaning. The night god surname, the moon given name, and the English reading laid over both give the character a name that is a small act of forgery, a label that does not say what it appears to say, which is the most Light Yagami detail in the entire series.

The wordplay completes itself at the end. Ohba has pointed to the final scene of the manga, in which Kira's worshippers gather after Light's death, and noted liking that it takes place under the light of the moon: the deeper significance, in the writer's own words, of a hero named Moon who insisted on being read as Light. On a Japanese cover or title page, the furigana gloss is the tell: where you see 月 carrying the reading Raito, you are looking at the name exactly as its author built it.