Kokoro no Chizu (ココロのちず)

"Kokoro no Chizu" (ココロのちず) is a song by the Japanese girl group BOYSTYLE. It was used as the fifth opening theme for the Toei Animation television anime One Piece (ワンピース) and was released as a single on November 17, 2004.

mizue wrote the lyrics, Kensei composed the music, and HULK arranged the song. The single reached No. 17 on the Oricon weekly singles chart, and the song later appeared on ONE PIECE 25th Anniversary BEST 1999-2024 [Limited Edition], released on April 23, 2025.