South North Story

EC 501~ and 2008 Akuno-P and Unimemo-P say this is a song about an encounter of two Rins from different worlds.
 * Nicovideo broadcast

Some fans interpret one is just Kagamine Rin and the other is Riliane Lucifen d'Autriche from Daughter of Evil. It is based on a motif picture that looks very similar to a motif picture of the Evil Series' Rin and Len standing back-to-back (a princess Rin and a butler Len) along with a brief shot with a princess looking similar to the Daughter of Evil. However, this is not stated directly at all by Akuno-P, and is purely fan's presumption. The song can be alternatively considered as a "crossover". This song is also given keywords:「ごきげんいかがですか」(How are you doing?).

Speculative Plot
Some time in the distant future in Japan, Rin and Riliane stumbled across each other at a mysterious traffic crossing. Both of them were baffled by the fact that the two of them exactly resemble each other but they soon became fast friends. While having drinks, Rin talks to Riliane about all the good and bad things that happened to her at school while Riliane talks to Rin about her tragic past all the way to the events of Regret Message. Len also appears, strumming on his guitar.

In the end, Rin and Riliane had to part ways, but both of them had high hopes that they would meet again at the crossing some day.

Characters
Rin Kagamine(ACT1) as Riliane Lucifen d'Autriche

Rin Kagamine(ACT2) as Herself

Len Kagamine as Himself