1998 saw the release of the band's first CD, E.F.Y.L., which found the Panic Smile sound moving in a more hardcore-influenced direction. The same year, the band relocated to Tokyo, with Torii departing, and the band recorded 1999's We Cannot Tell You the Truth Again as a trio. The addition of Ishibashi Eiko on bass later made the band a quartet again, but Ooishi's departure and the reshuffle of Ishibashi to drums and Yasuda to bass returned them to a three-piece soon after. New York native and jazz guitarist Jason Shalton joined towards the end of 2000 to finally fix the band into a stable four-piece, and it was this lineup that recorded 2001's 10 Songs 10 Cities, with Ishibashi temporarily taking over lead vocals. 2002's Grasshoppers Sun saw the band's sound developing further, with Shalton's work with Date Course Pentagon Royal Garden possibly rubbing off on the band, and aggressive funk punk sounds reminiscent of the Pop Group emerging. This album also saw the beginning of Panic Smile's association with producer AxSxE, of the Tokyo indie bands BoAT and Natsumen.
After the breakup of his band Number Girl in late 2002, Mukai Shutoku teamed up with Panic Smile for a series of gigs. Meanwhile, Panic Smile remained active with their own musical projects, with Ishibashi performing as a solo artist, as well as in the duo Ishibashi Eiko x Achiko and collaborating with Yoshida Tatsuya of Ruins. Tokyo's Rhythm Tracks label re-released E.F.Y.L. and Scale Kit 1/72 100% Plastic together on one CD, while the band's new material, 2004's Miniature and then 2007's Best Education, saw the band's poppier and more experimental tendencies developing in tandem, with some tracks drawing comparisons to Captain Beefheart and others resembling the twisted pop of Wire's more melodic moments. ~ Ian Martin, Rovi