Tanaka-kun's love (observation) diary.
Specially recorded:
-Nakajima-kun's behavior
-The food Nakajima-kun ate
-Nakajima-kun's clothes
-Nakajima-kun's words
-Nakajima-kun...
-Nakajima...
...
... A yandere love story written from both sides' points of view. (One chapter is divided into Nakajima and Tanaka's perspectives)