Excellent location just 1 minute walk from the nearest Metro station, 1 minute from the supermarket and right above a convenience store. You can walk to downtown Shinjuku in 12 minutes and it's off a main road where there are lots of buses (we took one to go to Shibuya). The check-in and check-out are done on an iPad in the entrance, and they give you the entry codes for the building and for your apartment. It was quick and easy.
The apartment was great, it was exceptionally clean with plenty of toiletries, toilet rolls, detergent for the washing machine, coffee sachets and slippers. Lots of household items included for your convenience, like a huge lint roller, vacuum cleaner, ironing board and iron, clothes hangers, drying rack for small items. The washing machine was great, and I loved the heater/fan in the bathroom where you can set it to 'dry' mode and it will dry your wet clothes in a few hours. There's a kettle, microwave, fridge with freezer compartment, electric stove and cutlery and utensils for cooking. I loved that there were 3 sinks (in the toilet, next to the shower room and in the kitchen) so it meant no one had to wait to brush their teeth.
There are many detailed instructions (with photos) showing you how to open the sofa beds, use the electronics, how to sort/dump the rubbish, and even recommendations for local shops and restaurants. They also include how to get to and from the airports and how to call a taxi (although I could not get the Taxi Go a