Natsu no Hi no Labyrinth

 is the second digital single released by Happy Kuru Kuru.

It was released on July 18, 2016.

Digital Single Information

 * Lyrics, composition, and arrangement: Yunomi (ゆのみ).

Tracklist

 * 1) Natsu no Hi no Labyrinth (夏の日のラビリンス; Labyrinth of a Summer Day)

Featured Members

 * Kinoko
 * Nono