Kawaranai Tsuyosa

 is the sixth single by Iguchi Yuka.

CD

 * 1) Kawaranai Tsuyosa (変わらない強さ)
 * 2) Valentine Eve
 * 3) Kawaranai Tsuyosa (変わらない強さ) (Instrumental)
 * 4) Valentine Eve (Instrumental)

Anime Edition CD

 * 1) Kawaranai Tsuyosa (変わらない強さ)
 * 2) in flames
 * 3) Kawaranai Tsuyosa (変わらない強さ) (TV size)
 * 4) Kawaranai Tsuyosa (変わらない強さ) (Instrumental)
 * 5) in flames (Instrumental)

Limited Edition DVD

 * 1) Kawaranai Tsuyosa (Music Video)
 * 2) Documentary Of Iguchi Yuka “Kawaranai Tsuyosa”
 * 3) TV-SPOT

Anime Edition DVD

 * 1) Kawaranai Tsuyosa ("Heavy Object" Non-Telop ED)
 * 2) in flames (Music Video) (Animation ver.)

Kawaranai Tsuyosa

 * Lyrics zopp
 * Composition: toku
 * Arrangement: toku

Valentine Eve

 * Lyrics: Satomi
 * Composition: Suzuki Kazushi, Nagasawa Chiaki
 * Arrangement: Sasaki Hiroshi

in flames

 * Lyrics: Kisuke
 * Composition: Watanabe Takuya
 * Arrangement: Watanabe Takuya