きえないひとみ。 (Kienai Hitomi.)

Background
The song was first uploaded on September 17th 2008; and serves as the last track to the series Putin-P Series part 2. It became overall the most notable song composed by Putin-P from his Putin-P series with over 200,000 views to date.

Kienai Hitomi tells how Rin and Len tries to let go of the past; while Miku mourns her fiancee Ronald McDonald by doing drugs and eating fries. Due to the song's complexity, a more detailed explanation on the song can be read on the section in the Putin-P Series' page.

In Putin-P's album Mienai yoru ni, Kienai Hitomi, a version "without" Ronald's voices, Sazae, or Fune is featured in the album.