エータ・ベータ・イータ (Eta Beta Eta) is a high-energy crossover track from the circle of composer ルゼ (luze), originally introduced in ONGEKI R.E.D. PLUS and ported to maimai DX UNiVERSE PLUS in September 2022. Clocking in at 186 BPM, the song is built around a clever linguistic puzzle: its title strings together the Greek letters Eta (Η), Beta (β), and Eta (η) to form "Ηβη", the name Hebe, goddess of youth in Greek mythology and daughter of Zeus and Hera. This mythological wordplay places the piece as the third entry in an informal trilogy alongside ルゼ's earlier works ZEUS and HERA, with all three tracks sharing thematic ties to the "PANDORA BOX" / "PANDORA FOX" universe established by the composer's BOF2005 entry. In ONGEKI, the song's genre is designated PANDORA FOX, and the jacket artwork nods to the franchise's recurring fox motifs while also depicting the vertical-note patterns and arrow imagery found in HERA's music video. The maimai MASTER chart, designed by チャン@DP皆伝 (Chan@DP Kaiden), is notorious for its relentless barrage of vertical note streams in the latter half, a signature of ルゼ's compositional style. A brief rest section near the end visually spells out "ηβη" (H·b·H) via slide note placements, rewarding attentive players with an in-joke that mirrors the title's Greek-letter gimmick. Intermittent "ばーか" (baka / "idiot") voice clips pepper the track, further reflecting the playful, self-aware tone that runs through the composer's body of work.