Takada-san is a great host! I stayed over with 6 persons + me (7 total) and we fit just fine, despite having too much luggage. 4 people, would fit wonderfully if you don't mind sharing beds. The place offers everything, so I could cook during all my stay! The only "problem" is you can't use too many amenities at a time (especially the microwave and the stove at high temperatures), otherwise the energy will shutdown. But it comes back after a few seconds. It's very well localized. You pay only 160 yen to visit the famous Shibuya crossing or Shinjuku for some shopping. Every time I needed something or asked Takada-san a question, she answered promptly and very politely. She can answer in English too. I highly recommend you stay in this apartment!