I have noticed that a lot of Japanese people eat by themselves in restaurants and cafes. This is vastly different compared to America and I absolutely love this idea.
Eating with people is always fun but being able to decided where and what to eat for yourself is even better. But in America eating by yourself even in a cafe is looked at like you are slightly strange and taking up a precious table that could sit more people than your lonely self. So I admit, I have never sat at a table by myself outside of the University library while in America but now I do it regularly.
The Japanese sit, study, read, and even sleep at tables in cafes and eat (no studying, or sleeping here!) in restaurants all by themselves. This is seen as totally normal and common place. Restaurants and some cafes provide a single style of seating for anyone who comes in alone.
A popular spot by Takadanobaba Station is Mister Donut, where the hot coffee comes with free refills. Totally worth checking out by yourself!
Talk to you soon,