Germaines probably has a website and you can buy on line. If not, I'm sure you can do it by phone. Last choice, the activity or concierge desk at you hotel.
Here is my choice for a restaurant in the Waikaki area. The name is Hau Tree Lanai.
Located in the New Otani Hotel (walk along Waikaki in direction of Diamond Head. Pass the Honolulu Zoo and the first hotel you come to.
Dinner is served on a Lanaii (patio) covered in giant hau trees. Book so you will be there for cocktail and dinner at sunset. Food is outstanding and plentiful. Service impeccable and the view is unsurpassed. Twinkle lights and tiki torches are lit at sunset for a lovely setting. Prices , by Honolulu standards are reasonable.
You should make a reservation, call directly or hotel cocierge can do this for you.