The song is about a spoiled girl who believes herself to be a "princess" that the world revolves around, and her struggles with falling in love with a standoffish boy. There are many PV variations for this song, but the narrator is almost always portrayed as a short-tempered and fickle Miku (interesting because of the meek and sweet-tempered manner that Miku is often portrayed with) but with a "tsundere" side.
In addition to the Miku version of World Is Mine, there is an official sequal called I'll Teach You (Oshiete Ageru in romaji) sung by Nagi (a female singer in Supercell). Also, there are famous covers by other vocaloids including Kaito, Rin/Len Kagamine, Gakupo Kamui and Meiko. The lyrics in these covers are changed so that they match up with each characters perspective. There is a version for nearly every character.
"World is Mine" is very popular among female singers on Nico Nico Douga and Youtube, and has received multiple covers.
SEGA has removed this song twice from Youtube over copyright claims due to its involvement in the Project Diva games. However, despite it featuring in their games, SEGA does not own the copyright of the song.
This song is widely considered and accepted as Miku's most popular, well-known, and favorited song.
Because of this, many have considered it to be Miku's theme song.
The original 39's Giving Day Concert Video on YouTube received over 20,000,000 views before the YouTube account was deleted. This made it the most watched Vocaloid video on Youtube.