"That Blue Sky Feeling" is a slice-of-life manga that explores themes of friendship, self-discovery, and acceptance through the interactions of its central characters. The story begins when Noshiro, a high school student known for his cheerful and outgoing personality, notices a classmate named Sanada sitting alone on the school rooftop. Intrigued by Sanada's aloof demeanor, Noshiro decides to befriend him, despite warnings from others that Sanada is rumored to be gay and should be avoided.

As Noshiro persists in his efforts to connect with Sanada, the two gradually form a tentative friendship. Through their conversations and shared moments, Noshiro begins to question his own assumptions about identity and relationships, while Sanada, who is indeed gay, navigates the challenges of being open about his sexuality in a society that often marginalizes LGBTQ+ individuals. The narrative delves into Sanada's past experiences, including his struggles with rejection and self-acceptance, as well as his cautious optimism about forming meaningful connections.

The story also introduces Ayumi, a childhood friend of Sanada, who provides additional insight into his character and serves as a bridge between the two protagonists. Ayumi's presence highlights the complexities of friendship and loyalty, as she supports Sanada while also encouraging Noshiro to reflect on his own motivations and biases. The dynamic between the three characters evolves as they confront societal expectations, personal insecurities, and the nuances of human connection.

Throughout the series, the narrative maintains a grounded and empathetic tone, focusing on the emotional growth of its characters rather than dramatic plot twists. The interactions between Noshiro and Sanada are central to the story, as their friendship becomes a catalyst for mutual understanding and personal development. By addressing themes of identity, prejudice, and the importance of empathy, "That Blue Sky Feeling" offers a thoughtful exploration of the challenges and rewards of forging genuine relationships in a world often marked by misunderstanding.