It was a great stay at her place.
The house owner Sayoko san was really friendly and kind, and she helped us by advising us when we got sick.
The room was comfortable and spacious enough for 2 people. The room had English and Korean guidebooks for tourists and that helped us to decide where to explore in Tokyo.
One thing that gave us trouble was the portable wifi. It would always drop connection while on trains. It would be better if you get a SIM card or a portable wifi router for yourself when you stay there as a tourist.
I would definitely stay there again!