"Shijō no Jinsei" (Japanese: 至上の人生, "A Life Supreme") is a song by Japanese musician Ringo Sheena. Used as the theme song for the drama Marumaru-zuma, it was released as a single on January 28, 2015.

On November 5, 2014, Ringo Sheena released her fifth studio album Hi Izuru Tokoro, her first after parting with her band Tokyo Jihen. Four of the songs featured on the album were used as Japanese television drama theme songs: "Ariamaru Tomi" for Smile (2009), "Carnation" for the morning drama Carnation (2011), "Jiyū e Michizure" for Ataru (2012) and "Irohanihoheto" for Kamo, Kyōto e Iku.: Shinise Ryokan no Okami Nikki.

Before the same time of the release of "Shijō no Jinsei", Sheena was also commissioned to write a song for boyband SMAP, "Karei Naru Gyakushū" (華麗なる逆襲, "Magnificent Counterattack"), which was used as the theme song for the drama Zeni no Sensō, a Japanese remake of the South Korean drama War of Money (2007) starring SMAP member Tsuyoshi Kusanagi. The song was released as a part of SMAP's single "Karei Naru Gyakushū" / "Humor Shichau yo" on February 18, 2015.

The song was written as a tribute to Marumaru-zuma screenwriter Kazuhiko Yukawa and the drama's production staff. Sheena considered the "light" of leading actress Kō Shibasaki as she created the song, and how Shibasaki's presence would affect the song. Sheena was inspired to write about how love reveals the true self. The phrase Shijō no Jinsei was a lyric originally found in her previous single "Nippon".

The song started airing as Marumaru-zuma's theme song from January 14, 2015 onwards. As the drama's theme song, it was used in promotional activities related to the drama. The physical single was released on February 25, a month before the video release of Sheena's concert tour Ringo-haku '14: Toshi Onna no Gyakushū. The song was performed at Music Station on February 27, and at Count Down TV on February 28.

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