Daimaru's basement food floor saved us multiple times when dealing with different food preferences in our group. The variety is great - everything from traditional Japanese delicacies to Western pastries, with plenty of ready-to-eat options. The quality is exactly what you'd expect from a high-end Japanese department store, but you can still find reasonably priced items.
What makes it ideal for families is how you can mix and match - grab some sushi here, a sandwich there, maybe some high-end pastries for dessert. The seating area means everyone can get exactly what they want and still eat together. Plus, watching the impeccable food presentation and service is entertainment in itself.