Yoasobi is a Japanese pop duo formed in 2019 by Sony Music Entertainment Japan. It is composed of musician and record producer Ayase and singer-songwriter Lilas Ikuta, under the moniker Ikura. With the slogan "novel into music", the duo originally released songs based on selected short stories posted on Monogatary.com, a social media website for creative writing operated by the label. Sources later also come from various media like stories written by professional authors, books, letters, plays, etc.

Rising to prominence during the COVID-19 pandemic in Japan, Yoasobi's debut single, "Yoru ni Kakeru", spent six non-consecutive weeks atop Billboard Japan Hot 100 and topping its 2020 year-end chart, as well as receiving the first ever diamond certification for streaming from the Recording Industry Association of Japan (RIAJ). Besides "Yoru ni Kakeru", three other songs were certified diamonds: Blue Period-inspired "Gunjō", Beastars opening theme "Kaibutsu", and Oshi no Ko opening theme "Idol"; the latter set the record for the longest-running number one in the Japan Hot 100 history for 22 non-consecutive weeks, and the first Japanese act to top the Billboard Global Excl. US, as well as the 2023 nineteenth best-selling global song, according to the International Federation of the Phonographic Industry (IFPI).

Yoasobi released three Japanese-language EPs: The Book, The Book 2 (2021), and The Book 3 (2023), which all peaked at number two on the Oricon Albums Chart; and three English-language E-Side (2021), E-Side 2 (2022), and E-Side 3 (2024). Outside their discography, the duo collaborated with four Naoki Prize-winning novelists—Rio Shimamoto, Mizuki Tsujimura, Miyuki Miyabe, and Eto Mori—to publish short story collection Hajimete no in 2022, and performed the songs based on each story. Yoasobi's accolades include multiple CD Shop Awards, Japan Gold Disc Awards, Japan Record Awards, MTV Video Music Awards Japan, Reiwa Anisong Awards, and Space Shower Music Awards.