1. Kakiyasu Sanshaku Sansun Bashi Lumine Shinjuku Shop「柿安三尺三寸箸 ルミネ新宿店」mery.jp
Inventive dishes from Japanese, Western and Chinese cuisines are on offer at this reasonably priced restaurant. There are many dishes using fresh vegetables too.
Lumine Shinjuku Lumine 1, 7F, 1-1-5 Nishi-Shinjuku, Shinjuku-ku, Tokyo
http://www.kakiyasuhonten.co.jp (Japanese only)
2. 「Cafe Rendezvous」uds.gnst.jp
Dishes of the day are on offer for main, rice, pasta, soup, and dessert at the buffet counter of this dining place within the hotel. There are also good range of French baguettes and salad bar. The place is very popular among female customers at lunch. Free Wi-Fi is available.
ibis Tokyo Shinjuku, 7-10-5 Nishi-Shinjuku, Shinjuku-ku, Tokyo
This restaurant is located on the 3rd floor of Citadines Central Shinjuku Tokyo. The extensive menu of lunch buffet changes daily. 90 minutes per session and rather reasonable for a buffet at a hotel dining room.
Citadines Central Shinjuku Tokyo, 1-2-9 Kabukicho, Shinjuku-ku, Tokyo
http://www.citadines-ccst.com/index.html (Japanese only)
4. Kuzushi Kappo Kakurebo Oniwa「くずし割烹 隠れ房 御庭」yaplog.jp
Japanese-style buffet at lunchtime is a big hit with no time restrictions. Plus, the restaurant is just 2-minute walk from the station.
Shinjuku NOWA Bldg. 7F, 3-37-12 Shinjuku, Shinjuku-ku, Tokyo
5. Erawan Shinjuku Higashi-guchi Shop「エラワン 新宿東口店」youpouch.com
You can enjoy lunch buffet at this Thai restaurant. Rice dishes, Thai noodles, and many other Thai dishes are available, including the increasingly popular Thai ramen. Course menu combining lunch buffet and shabu-shabu style hot pot dish is also on offer.
Humax Pavilion 4F, 3-28-10 Shinjuku, Shinjuku-ku, Tokyo
http://www.erawan-jp.com/info/ (Japanese only)
6. 「PIZZA SALVATORE CUOMO ＆ BAR」tabelog.com
Pizza is the signature dish of this restaurant, so naturally pizzas are included in lunch buffet along with pasta, salads, antipasto, and desserts. There are around 20 to 25 variety of Italian dishes available. Soft drinks are available too. Children are welcome.
Shinjuku Nomura Bldg. B1F, 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo
http://www.salvatore.jp/restaurant/shinjuku/index.html (Japanese only)
7. Restaurant Prince Viking (レストラン プリンスバイキング[ブッフェ])mery.jp
This restaurant within Prince Hotel offers buffet-style breakfast, lunch and dinner. The price is rather reasonable for a hotel standard yet the quality of food and service are awesome.
Shinjuku Prince Hotel B2F, 1-30-1 Kabukicho, Shinjuku-ku, Tokyo
8. Platinum Buffet Odakyu Shinjuku Mylord Shop「プラチナビュッフェ 小田急新宿ミロード店」tabelog.com
It’s a good, value-for-money buffet restaurant offering tasty dishes so there is always a long line of customers waiting on weekdays so making a reservation is strongly advised. From meat, pasta to salads and desserts, everything is of satisfactory level in terms of taste and quantity. This is a must-go place for lunch buffets.
Shinjuku Mylord 9F, 1-1-3Nishi-Shinjuku, Shinjuku-ku, Tokyo
9. Ristorante Carriera 「リストランテ カリエラ」restaurant.ikyu.com
Popular Italian restaurant offering good buffet dishes, many of which using fresh vegetables, at an affordable price. Because it’s extremely popular, brace yourself for a long waiting line of customers.
Hiltopia B1F, 6-6-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo
http://hitosara.com/0006036969/ (Japanese only)
10．Blumare Shinjuku Shop「ブルマーレ 新宿店」tabelog.com
This Italian bar style eatery offers buffet at lunchtime which includes all-you-can-eat pizza. Many original dishes change monthly, if not weekly. In addition, original curry with rice is offered exclusively for this lunch buffet.
Shinjuku Lion Kaikan, 3-28-9 Shinjuku, Shinjuku-ku, Tokyo
(This information is accurate as of June, 2015.)