"Alya Sometimes Hides Her Feelings in Russian" centers on the dynamic between Alya, a half-Russian transfer student, and her classmate, Kuze, who sits next to her in class. Alya is known for her sharp wit, intelligence, and fluency in Russian, which she often uses to express her thoughts and feelings in a language most of her peers cannot understand. Kuze, on the other hand, is a laid-back and observant individual who happens to understand Russian, though he keeps this knowledge hidden from Alya. This creates a unique dynamic as Kuze becomes privy to Alya's unfiltered thoughts, which she believes are safely concealed.

The narrative explores their evolving relationship as Kuze navigates the challenge of responding to Alya's candid remarks without revealing his understanding of Russian. Alya's dual nature—her composed, aloof exterior contrasted with her vulnerable, emotional inner thoughts—adds depth to her character. Kuze's ability to see through her facade allows him to connect with her on a deeper level, even as he struggles with how to approach their interactions. The story balances humor and heartfelt moments, with Alya's Russian outbursts often leading to comedic misunderstandings or poignant revelations.

As the series progresses, the focus shifts to the growing bond between Alya and Kuze, highlighting themes of communication, vulnerability, and the complexities of human relationships. Supporting characters, such as their classmates and friends, contribute to the narrative by providing additional perspectives and interactions that enrich the central storyline. The interplay between Alya's guarded personality and Kuze's quiet perceptiveness drives the plot, creating a compelling exploration of how people navigate their emotions and relationships.