ぼくたちいつでも しゅわっしゅわ！ (Bokutachi Itsudemo Shuwasshuwa!, "We're Always Fizzy!") is the signature theme song of maimai でらっくす Splash, released on September 17, 2020. The track was composed by Hige Driver (ヒゲドライバー), returning to the maimai series for the first time in roughly five and a half years since his previous contribution "oboro" from the ORANGE album. The vocals are performed by two professional voice actors, Rie Murakawa (村川梨衣) as Limekkuma (らいむっくま) and MoeMi as Lemonkkuma (れもんっくま), both making their debut appearance in a maimai song. The music video and in-game animation were directed by Hideaki Tsutsumi (ツツミヒデアキ). The song's effervescent, high-energy pop sound mirrors the theme of the Shuwashuwa Area (しゅわしゅわちほー), a fictional attraction zone built around lime-green carbonated springs, soda pools, and hot springs, all connected by a network of water slides. The lyrics take the form of a playful back-and-forth between the two bear mascot guides, with call-and-response chants, counting exercises ("たん！さん！たん！さん！"), and the recurring onomatopoeic refrain "しゅわっしゅわ！" mimicking the fizz of carbonation. At just 1 minute and 52 seconds, it is a compact burst of bubbly pop designed to match the Splash version's soda-themed aesthetic. The Re:Master chart, added on September 9, 2022 in UNiVERSE PLUS, is notable for its extreme Tap-note density, 647 Tap notes out of 764 total, an unusually high ratio for a Re:Master chart. The chart designers leaned into the song's playful identity by signing the Re:Master as "いぬっくまとボコっくま" (Inukkuma and Bokokkuma), a pun on the song's own mascot duo Limekkuma and Lemonkkuma.