Where's Halmoni? by Julie Kim (2017)
Two young children pay a visit to Halmoni (grandmother in Korean), only to discover she's not home. As they search for her, noticing animal tracks covering the floor, they discover a window, slightly ajar, new to their grandmother's home. Their curiosity gets the best of them, and they crawl through and discover an unfamiliar fantastical world, and their adventure begins. As they continue to search for their grandmother and solve the mystery of the tracks, they go deeper into a world of Korean folklore, meeting a number of characters who speak in Korean along the way, and learn more about their cultural heritage.