I get that it’s supposed to be some sort of imagery or metaphoric.I was able to google what they are, but the way I’m reading it they’re just kinda randomly singing…
FLYING BALLOON VINES!!!
…in the middle of a song. To use an English example, I’m understanding it like this…
Row row row your boat
Gently down the stream
MUSCULAR SUNFLOWER
Life is but a dream!
And sure, I can picture a muscular sunflower rowing its way down a stream, but it’s probably not the image they were going for… it’s really more a question of the use of the word 飛ばす with it to make it a complete thought in the rest of the lyrics.
It has a general association with love and affection. Kinda like singing about leaves falling in the air to symbolize autumn.
As for 飛ばす, I assume it’s just wordplay. Like what else would a balloon-vine be doing?
I’ll mark it solved and figure it out a year from now, I suppose. Maybe I’m looking for a more technical answer? As a vocalist and someone who absolutely nerds out on song lyrics (and it’s a large reason I’m studying Japanese!) I’ve sung some wacky stuff, but this one line has to be the more bizarre thing I’ve seen and I can’t get over it!!