What counts as an exclusive here
Bandai Hobby's Japanese item list tags some kits ホビーオンライン (Hobby Online). Bandai's Japanese release schedule files the same kits under 公式オンラインショップ販売商品, items sold through the official online shop, which is Premium Bandai, and most of their cards on the list link to Premium Bandai rather than to a Bandai Hobby item page. A second tag, ガンダムベース, marks kits sold at Gundam Base, and many of their names carry ガンダムベース限定 (Gundam Base limited). This page lists every kit with either tag, by the month shown on Bandai's Japanese list.
How Premium Bandai works for US buyers
Bandai's English hobby site links its Bandai Hobby Online Shop on Premium Bandai USA, which describes that shop as "the official online store for some exclusive items". Premium Bandai USA runs its own pre-order listings with "Pre-order" labels and a shipping information page, so the month in our table is the Japanese month, not a US pre-order window or a US delivery date.
We do not read Premium Bandai's sites with software: its terms of use forbid robots and data mining. To see whether a kit is offered in the US, what it costs in dollars and when the pre-order closes, open Premium Bandai USA yourself. Prices in our table are Bandai's Japanese prices with 10% tax as listed today.
Sources: Bandai Hobby Site (Japan) item list, Hobby Online filter; Bandai Hobby Site (Japan) item list, Gundam Base filter; Bandai Hobby Site (English), link to the Bandai Hobby Online Shop; Premium Bandai USA's shop description and pre-order labels as quoted in our where to buy Gunpla in the US guide (read October 11, 2026).