The Manager's Diary, known as the Factory Administrator's Diary (工場管理者の日記 Kōjō kanrisha no nikki ) in the original script, is a file that can be found in Resident Evil 3: Nemesis.
It can be found on a desk, near the Typewriter.
Today is my 30th birthday. I was transferred to this facility today. I am very happy because the work environment is very different from life in the university.
The disposal system has been completed. Using a special kind of gas, it can decompose the cells of the guinea pigs. We have to try this out before beginning practical usage of the system, since it is not 100% stable yet.
While I was checking the treatment room, the door shut, and I was locked inside. I couldn't get out for one hour. I guess even if you have the key card, it's useless when you are locked inside.
The guinea pigs we have to dispose of are increasing. The system is not working smoothly. The laboratory staff doesn't listen to my opinions and I am getting extremely frustrated.
We can't dispose of all the bodies and the quality of the liquid medicine is not good enough, either...
Though the function of the system decreases, the number of the bodies we have to dispose doesn't. The infection level has increased and the anti-bodies we are using is no match for the new mutation of the virus. Some of the workers have been infected by the disease. I have continued to work, but I always keep a gun with me. I must remember to save one bullet for me. I want to weep. I don't want to die here. I swear that I'll lose my mind if I imagine how painful the death will be...
The Japanese version of the 25 April entry describes the Manager having previously worked in a university lab, though the English version leaves it vague as to if he worked at the university or was a student. This university may be Raccoon University.
On the 7 June entry, the Japanese version goes into more detail, showing that the number of corpses to process aren't just increasing but are "unusually" high, with the Manager calling Dr. Birkin "Dr. Frankenstein".