Pluses: great communication; easy check-in; location is walkable to areas of interest and is real close to the JR yamanote line (which is beneficial for you if you bought a JR rail pass and is a pretty decent trainline regardless); apartment was clean and well-stocked; area is quiet (if that's what you want); family mart is a block away; toilet has a washlet and heated seats; water pressure and temperature are fine.
Minuses: comes with two beds, both of which are possibly too small for two people to sleep together in comfortably, so if you're a couple, you'll be sleeping separately; one of the beds is super squeaky; pocket wi-fi provided has a 500mb limit per day--I don't know if you'd go over that or not, but if you're planning on relying on the pocket wi-fi at this Airbnb, don't risk it, get your own pocket wifi from elsewhere;
Neutral:
Apartment is decidedly feminine with flower bedspreads, pink curtains, bedazzled pillows, headboard with hearts carved into it; there's no shower curtain in the shower...It's 50/50 here in Japan whether your shower will have one, it seems. This may just be a western comfort, but even though the entire shower room is made to get wet, it still gets a little annoying when all of your toiletries and the floor gets wet. I could also just be bad at showering; there's a low hanging chandelier in the "bedroom" that I kept bumping into and knocking around and was afraid I might inadvertently break.
If any of this sounds like nitpicking, it could be...but I don't know what you're looking for or what's important to you, so I figured I might as well mention it.
In the end, I would stay here again.