Midnight Sun is an extended play (EP) marketed as the sixth single of Japanese boy group JO1, featuring lead track "SuperCali".

On August 25, 2022, during a live Instagram talk session, JO1 announced that their sixth EP single, Midnight Sun, was set to be released on October 12.

[5] The lead track "SuperCali" is described to contain "a strong conviction that JO1 will continue to grow and burn with passion in every cell of their body".

[9] The word was introduced as one that "makes infinite possibilities come true" before the song was performed for the first time at the last Fukuoka show of the 2022 JO1 1st Arena Live Tour "Kizuna" on September 22, 2022.

"SuperCali" was made available for streaming on midnight the next day along with its performance video, which gained 10 millions views in just two weeks.

[16] "SuperCali" topped four chart components on Japan Hot 100 for CD sales, look-up, radio, and Twitter, but lost just shy of 30 points overall "in a fierce battle" against Kenshi Yonezu's "Kick Back".

[26] It eventually managed to be the group's sixth consecutive number-one on the weekly chart with 492,000 copies sold, surpassing their previous single, Wandering, and set a personal record for both physical and combined sales.