Sekaikan Ozaki is a Japanese musician, novelist, and voice actor, born on November 9, 1984, in Tokyo. He is best known as the vocalist and guitarist for the rock band CreepHyp, a group he formed in 2001. His real name is Yūsuke Ozaki.

Ozaki's primary career is in music, where he serves as the primary lyricist and composer for CreepHyp. He has also published novels and essays. His entry into voice acting is closely tied to his musical work. He provided the voice for the character Sabizaki-kun in the short-form anime series Hyper Positive Yogoremon. This 2021 series was directly inspired by his band CreepHyp's song Polico, which also served as the anime's theme song, and he was cast in a starring role alongside comedians from the duo Rubber Girl. Beyond this role, his voice acting credits include the 2017 live-action television drama adaptation of the manga Deep Sea Fish Man, for which he is listed in the voice acting cast. While his voice acting filmography is limited, his role in Hyper Positive Yogoremon represents a direct intersection of his songwriting and performance talents with animated media.