Utawarerumono: Lost Flag, the newest entry into the Utawarerumono franchise, has reached over 100,000 pre-registrations on July 11. Milestones achieved are 30,000 registrations (300 gems), 50,000 (600), 70,000 (600) and 100,000 (600). The current last available goal is at 150,000 users for 900 gems. 2,100 gems are enough for 7 gacha pulls. There is currently no information on how the gems are used, e.g. whether for summoning characters, premium items, and so on.
The campaign is open until the game officially goes live, upon which users will be able to collect the applicable rewards. You can follow the official Twitter account for more info or check out their website to pre-register.