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 and recording studio engineering. The group's last gig under the name "The Mongols" was 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.

Frontman Ely Buendia chanced upon the name "Pupil" while browsing a medical book. The band wanted a classic name for a rock band. Before using Pupil, they tried several other names, such as Villain, Lords of Nasdaq, The Gets, Trochlean, Traitors, Tyrel Corp and Narcom. They chose the name Pupil because Buendia liked the fact that it was the part of the eye where light enters. Guitarist Yan Yuzon likes its double meaning, as well as the “eternal learning” connotations of the name. Pupil's launch gig was on July 13, 2005 at the UP Bahay Ng Alumni.

Pupil had a hard time searching for a record label. They submitted their demo to several labels, but no one was more enthusiastic about the new material than the newly-merged Sony BMG. Incidentally, Ely left BMG Pilipinas in 2002 in the wake of his falling out with the Eraserheads. However, BMG accepted Buendia again like a "prodigal son," as he himself describes it in their debut album's insert.

The band is composed of five members who met in college at the College of Fine Arts of the University of the Philippines Diliman. Kamikazee's early gigs were mostly campus events in UP Diliman like the annual UP Fair. Before they were signed, they went by the name "Kamikazee Cornflakes," which was eventually shortened to its current state as "Kamikazee" was easier to remember. Their early shows included renditions of the songs "Tsinelas", a cover of Ariel Rivera's "Sana Kahit Minsan," and Britney Spears' Lucky. They were known for using expletives, suggestive movements, and references

to genitalia in their UP Diliman performances.

Kamikazee released their first self titled album in 2002. The album's carrier single was a rock cover version of the Britney Spears song "Lucky". In 2005, the band released 'Chiksilog' as part of the compilation album Rok On!. Other notable songs include 'Girlfriend', 'Ung Tagalog', 'Tsinelas' and their cover song of Ariel Rivera's 'Sana Kahit Minsan'. In 2006 they released their second album, Maharot. The carrier single of the album was 'Narda', which is thought to be about the fictional Filipina heroine Darna but is actually about a guy who is dreaming for a girl he couldn't reach. 'Narda' was hugely popular in 2006, and was one of the most played rock songs on the radio that year.

The band maintains close ties with another popular Philippine band, Parokya ni Edgar (PNE). Chito Miranda, PNE's vocalist, met the band members in college as he was also studying in the College of Fine Arts. In events with Parokya ni Edgar on the line-up, one band's singer would normally jam with the other band. On Parokya ni Edgar's songs Jay frequently joined Chito Miranda on songs like "Okatokat","Chikinini" and "The Yes yes Show." Jay was the back-up vocal to PNE's hit song "The Order Taker" while Jomal was on lead guitars. In turn, Kaye Abad, Chito's girlfriend, was on back-up vocals in Kamikazee's song "Martyr Nyebera."