Yoasobi is a Japanese musical duo formed in 2019. It consists of songwriter and producer Ayase and vocalist Ikura. Represented by the slogan "novel into music", the duo's narrative-driven songs are originally based on selected fictional stories posted on the website Monogatary.com. Later, sources also come from various media, such as fiction written by professional authors, books, letters, messages, plays, and social media posts. Known for its fast pace and complex structure, their music has been characterized as a blend of J-pop and Vocaloid music.