おひめさまになりたいのッ！ (Ohime-sama ni Naritai no!)

Background
The song was uploaded onto Nico Nico Douga on December 26, 2010. It's uploaded in between Christmas and the Kagamines' birthday; one of the tags of the video reads "Kagamine Birthday festival 2010"; meaning it's uploaded to celebrate the Kagamines' birthday and Christmas (as said in OSTER project's video description)

It's featured in the compilation "DEBUTANTE6" and has gained 300,000 views since, becoming one of Rin and OSTER project's most notable songs.

The song is about Rin's ambition to become a princess and that she will do whatever it takes to become one; she wants it so badly that she's dreamt it and daydreamed it. She also states that she is waiting for her "prince" who has yet to come.