Although it can be nice to stay in a single room which is quite comfortable, I found it out of the question that taking a shower in the morning is not allowed because of "Japanese tradition". We travelled around Japan for 2 weeks and this "tradition" is only enforced at Yoyogi. Our group had a very tight schedule and as a result we were not able to use the shower room at all.
Another negative aspect of this hostel is the lack of cleanliness: The condition of blankets and mattresses is quite appalling - the floors are covered with hair not matching the current guest.
Active guests who want to enjoy Tokyo should look for another place - which additionally might be a bit closer to public transport.

I just spent 3 nights at the Yoyogi Youth Hostel and was very satisfied with my stay there. All the rooms are single. The female hostellers are in one area and the men are in a separate section. The bathroom is shared, but just a 2 second walk from your room. There was wireless internet access in the women's lounge, and I could use my laptop there for free. However, I was told there would be a 500yen(about US$5) charge per day beginning in Dec. 2008. I was also told that there is a 6-day limit to how long you can stay there. Also, if you arrive before check-in, you can leave your bag at the main Youth Hostel office in another building. You can only take a shower or bath from 5-11PM, but be sure to bring your own towel. No towels are provided! There are several cafes and restaurants on the premises and a small store to buy snacks, etc. All the prices are very reasonable. This is a very peaceful and convenient place to stay. Not far from the train station and right next to Meiji Jingu Shrine which is like a big beautiful park, and also Yoyogi Park. You can also hop on the train and within minutes will be wherever you want to go in Tokyo. Where else can you find a place like this in Tokyo for 3000 yen a night? I recommend it!

Yoyogi Hostel would be a nice stay if you needed a place to put your stuff and go out for shopping or events like that, although the air conditioning and enviroment is pretty well sorted out it would be quite boring if you were to stay there by your self.
I thought the bathtub was a good japanese experience as well as the mirrors in the bathroom; they reminded me of the public baths, but then again you could fit three or four people in the bathroom. There is just one thing you have to bring along and thats a bath towel, otherwise you'll end up soaking wet when you come out with only the floor mat to wipe up.
Overall the hostel is quite well equiped since its only a few steps to the vending machines downstairs and also another thing to worry about is that the tumblers in the laundrey area don't work that well when you have bundles of clothes over three pairs of jeans, last time i used it it took me and two other guys 120 mins to dry a towel that was only used to wipe my face off along with two pairs of jeans. So watch out for the tumblers and i guess all thats left to do is have a nice stay, oh and mind the stairs, they tend to tire you quickly.