右肩の蝶 (Migikata no Chou)

Background
This song is Nori-P's most notable work. Originally sung by Rin, Len's version was released a month later and was also well received upon its release, becoming arguably more popular than Rin's original version. It is considered Len's most notable song, alongside Servant of Evil.

The song talks about a relationship that is in some way torturous, to the extent so that it is as regretful as it is pleasant for the singer.

The lyrics are clear, but are left vague enough to be interpreted in numerous ways. One interpretation is that the song is about someone that went out, hooked up, and was left feeling empty afterwards. Another interpretation is that the song is about Rin's love for Len and vice versa.

Though the song may have the same lyrics in both versions, the way the song starts, goes and ends are different. Rin's version has her singing clearly at the beginning, and ends with her chanting. The intro to Len's version has Rin whispering in the background; Len then screams and the song starts. Also, in Len's version, his voice is remixed a few times and he sings at a different pace throughout the course of the song, ending without Rin's chanting.

This song is featured in the EXIT TUNES compilation albums Vocalotwinkle,Vocalogenesis and Vocaloanthems.

Other media appearances
Len's version of this song is featured in the 39's Giving Day 2010 Concert, the MikuNoPolis 2011 Concert, the MikuPa Live in Sapporo 2011 Concert, the MikuPa Live in Singapore 2011 Concert, the 39's Giving Day 2012 Concert, the MikuPa Live in Hong Kong and Taiwan 2012 Concert, the MikuPa Live in Sapporo 2013 Concert and the MikuPa Live in Kansai 2013 Concert.

Sheet music for this song was published in Vocaloid Superselection piano solo.