Hiroshi Kitadani is a Japanese singer born on August 24, 1968, in Susa, Yamaguchi. He began his professional music career in 1994 as a member of the trio Stagger, which released an album through Warner Music Japan. Following his time with Stagger, he embarked on a solo career, releasing a self-titled album in 1999. Later that same year, he became a member of the musical group Lapis Lazuli, with whom he released a mini-album.

Kitadani is most widely recognized for his long-standing association with the anime One Piece. His solo debut single, We Are! released in 1999, served as the first opening theme for the series. He has since returned to perform several subsequent opening themes for the same franchise, including We Go! (2011), a collaboration with the band Kishidan on We Can! (2016), Over the Top (2019), and UUUUUS! (2024). In 2025, he released a cover album titled One Piece Cover Songs: Nakama no Shirushi X, featuring his renditions of eleven classic songs from the anime’s history.

Beyond his solo work, Kitadani is a prominent member of the supergroup JAM Project, which he joined in 2003. The group, whose name stands for Japan Animationsong Makers, is known for performing theme songs for anime, tokusatsu, and video games. His studio recording debut with the group was on the single Nageki no Rozario. Through his work with JAM Project, he has gained international recognition, including participating in the group's first world tour.

His discography includes full-length studio albums such as R-New (2008) and Real (2012), as well as a best-of collection titled Score (2014). His single Bokura no Spectra, released in 2023, peaked at number 32 on the Oricon charts. In addition to his work on One Piece, his anime theme song credits include Bakutou Sengen! Daigunder, Madan Senki Ryuukendou, and the opening themes for Gaist Crusher, for which he performed Bakuatsu! Gaist Crusher and Ex Dreamer.

Throughout his career, Kitadani has engaged in various collaborations. He formed the group SV Tribe with fellow musicians Masaaki Endoh and Aki Misato. He has also worked with arranger and former bandmate ats- (Atsushi Sato) and has received backing vocals from his JAM Project colleague Masami Okui on his solo album R-New. His musical identity is rooted in anison, a genre dedicated to anime and Japanese theme songs, characterized by powerful vocal performances. He has described his involvement with One Piece as the biggest turning point in his life, and he continues to be an active and significant figure in the industry, performing at events internationally.