[4] After Josef Alfonso suggested the band's concept, bassist Theo Dominguez proposed the name Sunami, having thought of the name around a decade prior, and Mike Durrett began writing the instrumentals at their friend Charles Toshio's home studio.

[7] The band's second live performance was a guerrilla-style show which around 2000 people attended on June 19, 2021, in San Jose alongside Gulch, Drain, Scowl, Xibalba and Maya Over Eyes.

[8] The performance was in a disused parking lot outside a warehouse their friend owned and the stage was built that morning by Gulch vocalist Elliot Morrow.

[2] This was followed by another outside performance on June 27 at the Lvl Up San Jose Punk Rock Flea Market with support from Fentanyl, Lead Dream, Connoisseur and Extinguish.

[13] DSCVRD magazine writer Harry Higginson stated that "Sunami are a quintessential beatdown band with every facet of their sound turned up to the maximum, blending elements of 90s metalcore and death metal into a pummelling, animalistic brawl.

"[20] Revolver magazine writer Eli Enis stated that "Their hyperbolic tough-guy lyrics and stupidly heavy songs incite violence wherever they hit the stage, but crucially, it's all in the name of good fun.

Alfonso in particular has cited East Coast hip hop as important to his writing style, referencing that the biggest influence on his lyrics and vocal flows for Demonstration as Big L.[2]