There aren't many breakfast places open during the day, and this hotel has a 7-11 on the ground floor for you to buy your breakfast foods (egg salad sandwich!). 7-11 ATMs are also best for fees if you use them to get cash, so this is super convenient.
There is a coin-op laundry, so you can pack lighter and save more room for souveniers. Some room types have in-room laundry as well.
We travelled with another family with children (4 adults 4 children total), and booked their connecting 2 bedroom apartments (4 bedrooms 2 bathrooms, 2 kitchens) and it was an amazing amount of space. Their bathrooms are split, with a toilet and mini sink in one room and the shower and bigger sink in the other -- per apartment. This really does help when you have a lot of people. Their website has plenty of accurate photos and videos of the rooms and a convenient floorplan view.
There are many free amenities that you can ask for from the front desk, and free coffee and tea bags available in the lobby. Convenient and secure luggage storage and transfer service is also available.
This hotel is conveniently located near the entrance to the Hibiya line (Hatchibori Station).