The streets around Tsukuba Center fill up in the early evening with researchers and university staff heading to the izakaya pubs that cluster along the pedestrian boulevard and the side streets behind the main shopping complex. An izakaya is somewhere between a pub and a casual restaurant — you order small plates of grilled skewers, edamame, fried chicken, potato salad, and sashimi alongside beer, sake, or shochu, and the evening can stretch as long as you like.
This is the best introduction to everyday Japanese eating culture that Tsukuba offers. Prices are modest, the atmosphere is informal, and most places have picture menus or plastic food displays in the window so ordering is manageable without Japanese. The standard approach is to order drinks first, then work through several rounds of small plates — no need to plan a full meal in advance.
The izakaya strip comes alive after 6pm and stays busy until around 10pm on weekdays, later on Fridays. Reservations are usually not needed unless you are a larger group.