We stayed at Irori for just one night and it's the kind of place that makes you think you might want to stay for a bit longer. We loved everything from the casual, tasteful and authentic interior and the comfy bed to cheerful, friendly and super helpful staff. We stayed in a deluxe room which was pretty small but in the end it was absolutely fine for our personal needs and the price we've paid. We had dinner served in the living/chill room - a japanese style fish barbecue with mushrooms and canned chicken. For £10 per head you can't ask for more, especially considering how cosy everything went with everyone sitting around the grills and chatting over a saké. All in all it was wonderful and we totally recommend it if you're in for something unfussy and casual and want to make a few friends along the way.
PS Don't believe the pillow comments in other reviews, it's BS. They are absolutely fine. Even more so, they're better than the ones in some fancier Tokyo hotels we've stayed before.