Stayed at Rihga Royal for a night before our day tour. I was impressed with the service of the staff and would recommend the hotel as a place to stay in Hiroshima. Two top reasons as to why, location and service.
1) Staff is pleasant and quick. We had a tour snafu and they helped us out, which was a great help. Additionally, I called with the company rate, and they worked with me to make sure I get the company rate based on the offering. They didn't see it in their system, but I sent them the screen shots and they honored it.
2) The hotel was just a 10 min ride via the trolley system. By taxi probably 5 min. It is located right next to a huge mall on one side and in front of the hotel, you have the Hiroshima art museum; to the left the sports complex; and past the museum there is a Hiroshima castle. So, you are close to everything.
3) We got the breakfast included. It wasn't anything special, but they are the only hotel that did offer fruit. Considering the prices of the fruit in Japan, that was very nice of them.
4) the room was nice size with a large bathroom. We got lucky to stay on 26th floor and the views were magnificent. So, ask for a higher floor. Oh yes, no king size bed. Queen.