Outside
There is a small door off the street and a sign above it. You walk through a narrow graffiti-filled hallway to access the room selection foyer.
Lobby
There is a light-up wall of photographs showing all of the rooms in the Black Beaver. You can tell which rooms are available because they will be lit up - occupied rooms are dark. Each photograph had a room number and a price for resting and staying.
At the end of the lobby is a counter where you announce which room you want. You cannot see the hotel proprietress but her hands are visible in the little money exchange window. She will tell you the cost for your room and you pay. You’ll need to say the room number (in Japanese) and tell them you plan to stay. When the money is squared away (don't expect a receipt, and plan to pay in cash), you can take the elevator to your room. The first number for each room indicates the floor (i.e. if you pick room 305, it is on the 3rd floor). Hop in the tiny elevator, select the appropriate floor and there will be a flashing light above the door indicating your room.
Inside
First of all, the room we stayed in was TINY. The lighting was dismal and we've never seen a love hotel room with natural light. With our luggage there was hardly room to walk around. Given the lighting, it was hard to say how clean was, but it felt a tad dingy. The bathroom and shower areas were well lit and looked clean.
To the right of the genkan was a sink with requisite beauty supplies just outside of a toilet room. The shower was behind the sink area and greatly resembled a business hotel or dorm room bathroom: very efficient and tiny.
The bed was around the corner from the bathroom area, tucked in between three walls. Our room had wave-shaped mirrors on the walls and ceiling and a Mickey and Minnie Mouse theme. There was a small refrigerator-esque vending machine with panties, vibrators, and beer. In the bedroom area was a tea set, tiny TV, a clock, and a 50-button radio. The mattress was thin and lumpy, but long enough for both of us. In the morning, we received a phone call to see if we’d made any room charges. This is a pretty standard conversation: you answer, they say some greeting and ask if you have purchased anything in the room that now you need to pay for. You say no. They say thank you, you say thank you, voila. We packed up and left the room by 10am. The phone call is an indication that it is time to go.
Leaving
We went out the same way we came in. This hotel seemed to know it was on the cheaper end of Osaka love hotels and wasn't overly concerned about discretion.