Junji Ito’s Junji Ito’s Cat Diary: Yon & Mu is a semi-autobiographical manga. First serialized as Itō Junji no Neko Nikki: Yon & Mū in Japanese manga magazine Monthly Magazine Z from the January 2008 issue to the February 2009 issue, Cat Diary was collected into a single volume in 2009 and translated into English in 2015.
Years of hard work1 have delivered horror manga artist J‑kun the life he covets. He has a brand-new home. He has a darling fiancée, A‑ko. However, to his growing alarm, he discovers A‑ko has dreadful plans, plans against which a simple writer/artist cannot hope to prevail.
Whereas J‑kun is a dog person, A‑ko is a cat person. A‑ko has a cat named Yon. Yon will be living with J‑kun and A‑ko.