If you are sensitive to stay in clean room, I do NOT recommend you to select this apartment since this apartment is NOT clean - even the suspected blood, hair, and other unknown black trash can be found in the bed after he/she confirmed the room was cleaned already!
Although the house owner responded to me after receiving my escalation ( sent the email to him with pictures on those dirty things), no further actions have been taken, that left us one sleepless night - at last, we even have NOT received any further feedback on our escalation, including one simple apology. To be honest, that is NOT normal Japanese way!
I admitted, we still have one issue in our own - we checked in at 11am around, but it was required at 3pm. After we have been aware of this, we immediately sent the message to the host, and apologized for our early check-in, also confirmed with him/her to take the full responsibility on the left luggage, then left very soon. But that would NOT deserve the dirty beds in my view.
It is really disappointed!
On the other hands, the location of this apartment would be good and convenient: 5 - 8 minutes walk to access many restaurants and metro. Again, if you don't mind the dirty things on your beds and prefer to convenience in terms of traffic and food, this apartment is still good.
The host is responsive to most of our questions, albeit some delays to certain questions that we have posted. The apartment is close to the metro station as described, and is in good condition and clean. Good security as the apartment building is only accessible for tenants with keys. The unit is rather spacious and just nice for stay of 5 people. Generally we enjoyed the stay, and will not mind to stay there again.