The Night Beyond the Tricornered Window (Japanese: さんかく窓の外側は夜, Hepburn: Sankaku Mado no Sotogawa wa Yoru) is a Japanese manga series written and illustrated by Tomoko Yamashita. It was serialized in the monthly yaoi manga magazine Magazine Be × Boy from March 7, 2013, to December 7, 2020. A live-action film adaptation was released on January 22, 2021, and an anime television series adaptation by Zero-G aired from October to December 2021.