A great space for a large group. Enough beds for those who aren’t used to sleep on tatami. The one shower is fine for us, and having washroom on each floor helped.
The air con for each floor is powerful but the staircase was hot in the summer cause we have to keep the mosquitoes out from the bedrooms.
Expect a bit of walking to subway station (10 min to the north station and 5 min to the south station). If you are traveling more to the east side of Tokyo, I recommend finding a place on that side, as it took us daily 1-2 hr to travel on subway to our destinations and that ate up a lot of our time.
Overall a great space for a large group.