I stayed at Masa's place for six weeks while doing an internship for university in Tokyo. I couldn't have picked a better place and location, I would highly recommend Masa's place for both long term and short term stays. The house was spacious, extremely spacious in Tokyo terms, and had everything you could need for your trip, including a washing machine, fully equipped kitchen, wifi, iron, bathroom, couch, dining table and desk.
The location was perfect, only a minute or so walk to Magome station on the Asakusa line. It takes about five minutes to Gotanda station on the train where you can change to the JR line.
It was lovely staying in Magome, a residential neighbourhood, where I could get to know the real Tokyo. I'm so glad I stayed in a residential neighbourhood rather than somewhere so busy like Shibuya.
Masa was an incredible host, going above and beyond expectations; meeting me at the station on arrival and making generous offers like driving me to the supermarket if I wanted to buy anything heavy (it's so close anyway!) and offering to meet me at the station with an umbrella on a rainy day on my way home from work. We were in constant communication during my stay to make sure everything was going well. I highly recommend staying at Masa's place!