Stayed there for one night during my 2-week trip of Japan. I decided on this place based on the positive reviews on Tripadvisor and I was very very happy with my choice! Location wise it is perfect - only minutes away (by foot) from the Peace park and museum. The centre of town or JR train station are only a quick bus ride away.

The hotel is located within a complex which serves as a function centre; the hotel rooms are on the top 2 floors of the building so you get a nice view of the city.

I stayed in a single room for about 3600 yen/night. Such good value for money compared to anywhere else I've stayed in Japan. The room was of decent size, very well-maintained and clean (I'm very fussy when it comes to cleanliness) and had everything you will possibly need from a hotel room.

Staff were great and spoke good English.

You can book your stay by email (they were very quick to respond) or by phone.

Overall one of my favourite hotels that I've stayed in Japan. Will definitely stay again and recommend to others.

We had a great time at the Aster Plaza. This is supposed to be a Hostel-type accommodation but really, it's much much more.
We booked a Japanese style room and it was amazing. Big, bright, quiet and super-clean, with all the amenities you could wish for and even more. Very friendly and attentive staff. The Hiroshima Memorial and Peace Park are two minutes away, but you can easily walk to busy streets and shopping malls around.
Highly recommended!

The Aster Plaza is not really a Hotel, nor is it a Hostel. It appears to be a function centre, that has accommodation on the upper few floors. Its in a great location for visiting the Peace Park and Museum. Approx a 5min walk straight up the street. WE arrived by bullet train. The easiest way to the Aster Plaza is the bus. Take the No,24 bus for “Yoshijima”from platform A-3 near south gate of Hiroshima JR Station, and get off at “Kako-machi”which is next stop from the Peace Park stop (about 25 minutes ride). You will see Aster Plaza across the road. Approx 190yen, pay cash in machine near driver.
We had a family of 4. Kids aged 15 and 12. We originally booked a Japanese style room for the 4 of us. However this was our first experience with a Japanese style room. After coming from Kyoto where we had two "double" rooms, the Japanese room seemed quite small. The price for the Japanese room was approx $280 total for 2 nights. We paid more than that per room per night in Kyoto. Ended up changing to 2 "double" rooms for an additional $28 total, ie $308 for two nights for 2 rooms, simply fantastic value. The rooms are your standard Japanese Western room, small bathroom (clean and does the job), 2 single beds (quite comfy), small fridge, kettle and LCD TV. Very little English content on the TV, but that seems standard for Japan. Thankfully the Sumo wrestling was broadcast in English every afternoon. Note there's usually an English button on all Japanese remotes, so if a program has English content it can be changed, but don't expect a lot of choice. Our 2 rooms overlooked the river (8th floor) and faced the Peace Park. They have washing machines and dryers, coin operated, 100yen, ask at reception. They also have a fully equipped kitchen if you need it, ask for key at reception. We didn't see anyone else staying in the hotel. It felt like we had the place to ourselves. This could be dependent on the type of functions being held at the Plaza. The reception staff were very very helpful, and had great English. The Aster Plaza isn't in the middle of the restaurant district, but there was a couple of small Okonomiyaki (google it, Japanese pancake, especially famous in Hiroshima) restaurants across the road. Ask reception to direct you to the Hana-Hana restaurant, small husband and wife setup. Our best meal in Japan.
Don't forget to go to Miajima Island to the south of Hiroshima, easy to get to from the Aster Plaza. I have already recommended the Aster Plaza to friends. You can't book online, but you can email them at reserve@hiyh.pr.arena.ne.jp to make a booking.

the aster plaza is a very good hotel, i stayed in a western style room. walking distance to the peace memorial park.
for 3700 yen it is a very good deal for the otherwise very expensive japan.
bathroom was clean, and the room was very quiet.
as i stayed on the 9th floor I could enjoy a wonderful view over hiroshima at day and night.