ココロ・キセキ (Kokoro・Kiseki)

Background
Kokoro∙Kiseki is one of the most popular and famous derivations of Kokoro.serves as a prologue of the original song.

Kokoro∙Kiseki tells the story of the scientist who created the robot in Kokoro. Short after create the robot, the scientist realizes she is missing something important: her heart. Wishing to share happiness and sadness with her, he begins to work tirelessly at creating a heart for her. However, the time is running out for his life will eventually come to an end. As he begins to lose hope, a "miracle" suddenly happens: he receives a message from the robot from the future, after she has created her own heart. The scientist obtains peace and passes away in tranquility.

Though there is no clue who the scientist is in Kokoro and despite in Kokoro・Kiseki, Len isn't explicitly portrayed as the scientist, due the popularity of the spin-off, many PVs began to depict Len as the scientist after the release of Jun-P's work.

This cover is featured in the EXIT TUNES compilation album Vocalogemini.