Streamer Cafe Shibuya is one of three branches of a popular and reliably good espresso cafe. The atmosphere is pleasant, the staff are friendly and quite a few of them fluent/native English speakers, which is always a bonus in Japan.
It’s a great place to relax with friends or tap away on your laptop for a couple of hours (ab)using their free wifi. There’s even a smidgen of outdoor seating, which is a nice touch in the warmer months.
Word of warning though, watch out for when the shop is hijacked (well most likely rented) for a fashion shoot though, best to avoid the place if you see a van parked outside and a team of runners hanging around. Unless you like repeated bright camera flashes with your coffee.