We stayed in Takeshi's place for two weeks.
Indeed he gave us a competitive price because he advised us that his place is still under construction, but he did not say to what extend. So don't be surprised if you enter a construction site.
Now, let's be positive:
We used a room on the first floor (2nd floor for Japanese counting) and since the room opposite our room was still under construction and did not host people in its bunk beds, we could use the quite new shower cabin and toilet for ourselves, instead of sharing them already.
Our room had newly smelling tatami mats and a low rise wooden framed bed. For westerners, be aware that it's still not the same than sleeping in a "real" bed. The room had neither a cupboard nor wardrobe, so be ready to live out of your suitcase. Luckily we could ask Takeshi for a mirror, a table and two chairs, which he provided so we could at least sit somewhere during our stay and dress properly, also.
Be very cautious with the Japanese style paper window frames used as curtains, because the window handle can easily tear them up. And you don't want to be charged for it.
Be aware that the house is located on a 4 or 5 lane main road and you would better sleep with earplugs if you intend to stay longer than 1 or 2 nights.
There was no kitchen (we were aware of that) and Takeshi told us he did not intend to build one. Thankfully, he installed a microwave in the shared area of the ground floor after I asked him to.
Also, you have to pay for the washing machines in the pictures, as we discovered once we arrived only.
Takeshi is very discreet, even if he lives on the last floor you rarely see or hear from him. But he is always available via airbnb emails if you need him.