ひとりにしないで。 (Hitori ni Shinaide.)

Background
The song was first uploaded on January 17, 2008. It's previous song; It's the End was Track 0, though both Don't Leave me Alone and It's the End are the first tracks of Part 1 and the series.

The song talks about how Rin doesn't want to be alone, she wanted to be with Len. She tried calling Len, and he gave a lame excuse saying, "I don't know how to use my phone". Len talked about the fight in Russia and he mentioned a few wrestling moves afterwards. For the next minute of the song, Rin kept on singing 'don't leave me alone', along with Ronald's "LAN LAN LUU".

Japanese and Romaji Lyrics
ヒトリニシナイデヒトリニシナイデヒトリニシナイデ x66 Hitori ni shinaide hitori ni shinaide hitori ni shinaide x66