Pupil is a Filipino rock band composed of Ely Buendia on lead vocals and guitars, Dok Sergio on bass and Wendell Garcia on drums. Pupil was formed when Dok Sergio from the bands The Teeth and Daydream Cycle joined The Mongols' line-up during the fourth quarter of 2004, making it a five-man band. The Mongols' bassist Yan Yuzon moved to third guitar duties while Dok Sergio handled bass. The transitional five-man line-up was witnessed in The Mongols’ last single and music video entitled “Heroine”. In May 2005, guitarist Jerome Velasco, a.k.a. J. Astro, left to pursue a career in producing, recording and studio engineering. The group's last gig under the name "The Mongols" was on July 7, 2005. Velasco’s departure shook things up for the group as they were trapped into the decision of whether to stay as a band or not. As they decided to continue and as they progressed, the band noticed that they were producing a different sound without Velasco on the lead guitar and decided to form a "new" band. “We got a better bass player and dumber guitarist,” jokes guitarist Yan Yuzon, who left bass playing duties to Dok Sergio to take Velasco’s place. Upon the determination of forming a “new” band, the group’s first move was to change their name.