Who Is the Sender?(2022)

Who Is the Sender? is a Japanese drama series following Kuwazuru Mitsuki, a second-year high school student whose class becomes consumed by an anonymous letter game. Their homeroom teacher introduces a deceptively simple rule: every student must write letters revealing their true feelings to classmates, but without signing their name. What begins as harmless pranks quickly escalates into raw confessions and dangerous secrets. As unsigned letters circulate, students obsess over their origins and contents, forcing uncomfortable truths into the open. Mitsuki becomes determined to identify who wrote to her, uncovering something far deeper than a classroom game. The letters gradually strip away pretense among classmates, exposing hidden worries and building unexpected connections, yet the mystery at the heart of the game threatens to unravel everything.