Hasira

Nice spot for lighter meal options

Hasira is located in the Okubo area of Tokyo, and I would recommend them if you're looking for a lighter meal option while you're in the city -- think along the lines of hearty salads and yogurt bowls and you're on the right track. They also have some panini lunch sets if you're looking for something with a bit more oomph to it. They're located super close to Higashi-Shinjuku station, so they get some points for ease of access, too.