雨とペトラ (Ame to Petra, "Rain and Petra") is a VOCALOID song by the producer バルーン (balloon), featuring the voice synth flower. First released on balloon's 2017 album Corridor (the song's original niconico upload is sm30789907), it later made its rhythm-game debut in CHUNITHM AMAZON PLUS in April 2019 before arriving in maimai でらっくす Splash PLUS on March 18, 2021 as part of the niconico & VOCALOID genre. The song also appears in オンゲキ R.E.D. PLUS, making it one of the tracks that crossed all three of SEGA's contemporary arcade rhythm games. The accompanying music video was created by アボガド6 (avogado6), a celebrated illustrator whose stark, grayscale-and-occasional-color art style defines the song's visual identity, the same jacket art appears across all three SEGA titles. The title pairs rain (雨) with Petra, likely invoking the ancient rock-cut city known for rose-colored stone eroded by time, mirroring the lyrics' imagery of a gray sky crumbling and rain washing over faded color. Balloon (real name Keina Suda / 須田景凪) is one of the most influential VOCALOID producers of the late 2010s, best known for his breakout hit シャルル (Charles). He later launched a parallel career as a singer-songwriter under his legal name while continuing to produce VOCALOID tracks. In maimai, the Master chart (level 12, constant 12.4) was designed by はっぴー and features a notably dense Slide-note layout, 106 slides out of 721 total notes, that rewards reading speed and spatial coordination. The Expert chart was designed by 隅田川星人. maimai uses a slightly extended edit of the song (2:21) compared to its CHUNITHM and オンゲキ versions (2:16).