II-V was produced by the Ring band, merging elements of rock music and orchestral music, partially based on Xenon's various musical elements.
The name of the song is written in roman numerals, II-V, and it's a type of upper chord progression. Usually it appears before the end of a phrase or song. As for this chord progression that usually appears in the "final part", what it represents is...
- This song might be a reference to the songs II and V.
- "II" and "V" are the numbers 2 and 5 written in roman numerals, meaning the numbers in the title equal 7. The song II is 7 minutes long, while II-V is 2:05 minutes long.
- The title includes the number 5. Not only could it be a reference to the song V, but, around the 5-minute mark in II, Vanessa says Ivy's name in a distorted voice.
- It also might reference Version 2.5 of Cytus II, where Crystal PuNK was first introduced.
- Just like V may be a reference to Vanessa, II-V may be a reference to Ivy, because, when pronounced in a specific way, it reads out her name.