Looking for a decent 1-room flat nearby Ruhr-Universität Bochum

I am Jihoon Chun, from Seoul, South Korea, who will begin Ph.D. study at the Ruhr-Universität Bochum from early April 2018.
I am looking for an one-room flat, preferably within an about 20-minute ride distance from RUB, with furnitures(bed, desk, chair, wardrobe and a kitchenette) and a washingmachine equipped.
As an organized and non-smoking/non-alcoholic person(male), I will keep the place clean and tidy throughout the period of my stay.
Since I am going to arrive in Bochum on April 3, it would be perfect if I could move in on that day.

Warm regards,
Jihoon Chun