Trapezium (トラペジウム, Torapejiumu) is a Japanese novel written by then-Nogizaka46 member Kazumi Takayama. It was initially serialized in Kadokawa Shoten's Da Vinci book and manga news magazine from April 2016 to August 2018. Kadokawa Shoten later published the novel in print with cover art by Tae in November 2018. An anime film adaptation produced by CloverWorks premiered in Japan in May 2024. A manga adaptation illustrated by Kina Kazuharu will begin serialization on Kadokawa Shoten's KadoComi website in Q4 2024.