Perhaps you could take a look at accommodation also for Tokyo, 30.4. - 4.5. and 11. - 14.5.? As always, I've made some reservations, but the offer wasn't much. As for location, we would prefer something livelier. It would seem that almost everyone recommends Shinjuku.There are so many hotels in Tokyo but you will encounter difficulty in finding affordable rate in weekends: 3rd May and 12th May (anyway are you planing to stay in Tokyo on 4th May?). Yes Shinjuku is lively place and very popular, but the room rate is higher than other places so if you have budget issue I don't think it is a must to stay in Shinjuku area.
I would recommend these three hotels. Of course they have some pros and cons and you should consider them.
Rihga Royal (sorry, it's not Loyal) hotel Tokyo.
30.4 to 3.5 (3 nights) luxury twin room, 442 euros.
https://uk.hotels.com/ho105822/?q-check-out=2018-05-03&FPQ=3&q-check-i...Pros: large room (38 SQM), shuttle bus service to/from JR Takatanobaba station. 4 star hotel. Waseda tram station and Waseda subway station nearby.
Cons: somewhat pricy.
IKIDANE HOUSE ASAKUSA HATAGO - Hostel
3.5 to 4.5 (one night) Standard Twin Room, Private Bathroom, 96 euros
https://uk.hotels.com/ho713392832/?q-check-out=2018-05-04&tab=descript...Pros: Inexpensive for this date (they offer same rate for Saturdays). Good user reviws.
Cons: Out of the Yamanote line. Far from train stations (maybe 20 min walk). Maybe the room is not spacious.
Hotel Metropolitan Edmont Tokyo
11.5 to 14.5 (three nights) Standard Room, 2 Single Beds, Non Smoking 363 euros (as usual, Saturday is more expensive)
https://uk.hotels.com/ho161114/?q-check-out=2018-05-14&tab=description...Pros: Close to train stations. Within the Yamanote line.
Cons: Saturday is out of your budget.
Sorry, but I canft say anything about the FujiQ. Maybe someone might give you good suggestions.