Akira Otoishi

Akira was one of the many people Keicho Nijimura shot with the Bow and Arrow while trying to find a stand user capable of killing his mutated father. Akira was one the many lucky ones to develop a stand after which point he became interested in them and how to create them.

[Spoiler] To further his goal on studying them he needed the Bow and Arrow which he forcefully took from Keicho leading to Keicho's death. [/Spoiler]

From there on he tormented several people, among them Josuke while trying to improve in the use of his guitar skills.

(Source: Wikia)