This design case presents a gamified dictionary learning intervention for away-from-school learning. Intended to be mobile, the game features AI speech recognition for practicing English words and phrases. We also introduce a second feature--an integrated teacher dashboard that addresses issues in traditional homework--a lack of immediate feedback and out-of-class monitoring. We recount the process narrative from ideation through collaborative development and the unique context of Japan. The design aims to free up class contact hours from vocabulary building, so more engaging activities could optimize learning. A negative case analysis highlights early design failures related to graphics and young learner sensibility, along with solutions. Despite being the first digital product from this lead designer, the user base quickly grew to 4,000 users at the time of writing. We drew methodological guidance from authors writing about the purpose, process, and aims of instructional design cases (Boling, 2010; Gray, 2020; Howard et al., 2011; Moore et al., 2023) to situate our narrative. The game is titled "The Gamerize Dictionary," but throughout the article, we often refer to it as a gamified dictionary to clarify its nature and avoid confusion with the less common term "Gamerize".