is the second single by Japanese band Princess Princess. Written by Kyà Âko Tomita and Kaori Okui, the single was released by CBS Sony on July 16, 1987. It was re-released on July 1, 1989 as the band's eighth single, which became their second of five consecutive No. 1 singles on Oricon's singles chart.
"Sekai de Ichiban Atsui Natsu" was originally released on vinyl in 1987 with "Vibration" as the B-side. As Princess Princess was relatively unknown at the time, the single did not chart. The song was used in the TV Asahi travel show . The song's original key is A.
The song was re-released in 1989 as a CD single with the B-side being a re-recording of the song (known as the ). The CD jacket was designed to resemble an airline ticket; the first edition release was colored gold while the regular release was colored pink. The Heisei version of the song was used in the TV Asahi travel show .
The song was remixed in the band's 1992 compilation album Singles 1987âÂÂ1992.
In 2001, TBS aired the drama series . It is not related to the Princess Princess song, though it is coincidental that Goro Kishitani, who starred in the drama, is married to former member Kaori Okui. To capitalize on the drama's popularity, SME Records reissued the song as a maxi-single with "Diamonds" on August 8.
To coincide with Princess Princess' reunion in 2012, the song was used by Sapporo Breweries for their Sapporo Ice Lager 7 commercial, featuring the band.
"Sekai de Ichiban Atsui Natsu" hit No. 1 on Oricon's singles chart and No. 2 on Oricon's year-ending chart in 1989 - second only to the band's other hit "Diamonds". It also sold over 865,000 copies and was certified Double Platinum by the RIAJ in August 1990.
All music is composed by Kaori Okui and arranged by Princess Princess.