Masami's place is very nice, even its not a very new apartment but its surely a comfortable one.
The location is good too, not so crowded but still very lively with small restaurants and bars. I love the apartment's area since there are lots of nice house (I think it a Japanese house, like those in Doraemon story), there is a good local restaurant with nice curry rice and beef rice just on the main street on the way to Masami's apartment.
About Masami, she is very nice although we just communication via texting. She prepared all of the useful tips/guide (on how to get to her place, how to use her amenities, how to separate trash...). She prepared everything you need and little snack and welcome note too (its a great hospitality even its small). I like the most is the little worldly-currency collection of Masami, which allow you to put your country currency :)
We might be the first two Vietnamese people stay there and put our country currency.
Thank you Masami again for great host, definitely a recommended place for those who will travel to Tokyo :)