Possible misinterpretations: "Shinseki" could be another place, but I'll go with Shinjuku. Maybe they're looking for a specific spot like a park (Shinjuku Gyoen), a restaurant, or a shopping area. They want the place to be a good place to stop (pause, rest) and be happy.
"Tomaridakara de nada happy" – "tomaridasu" is to stop temporarily. Maybe "Tomaridakara de nada happy" translates to "stopped, so just happy." Maybe they mean they stopped doing something and ended up being very happy. "High quality" could refer to food, a place, or an experience.
Putting it together: They might want a recommendation for a high-quality park or spot in Shinjiku where they can relax and be happy. Or maybe a place in Shinjuku where you can stop (as in take a break) and enjoy a happy, high-quality experience. I need to confirm the key points.