“에잇 (eight)” is a first collaboration of IU and SUGA. On the track, the two artists sing about living life as 28-year-olds. References to her age is a running theme in IU’s songs, past examples include, “Palette” and “Twenty-Three.”

The music video has a futuristic and digital concept, different from IU’s usual concept. The video is partially animated and partially live-action.

Fans theorize that this song is partially about IU’s loss of her three friends in the KPOP industry, SULLI (formerly of f(x)), Goo Hara, and JONGHYUN (formerly of SHINee). All three artists committed suicide and were actively battling depression at the time of their deaths.

Visual symbolism of two of her friends is used in the song’s corresponding music video, with JONGHYUN being the lizard as he was known to have a particular liking for the Pokémon Charmander.

And the white-dress-girl running through a forest being SULLI, who bears resemblance to the late singer and actress.