Momo Sakaki is a main protagonist in the story, known for his reserved and serious demeanor. From a young age, he lived next door to Nino Arisugawa, with whom he formed a deep bond through singing and a childhood promise that if they ever became separated, Nino's voice would serve as a guide to reunite them. When economic hardship forced his family to move away without warning, the sudden departure left Nino heartbroken. Years later, Momo resurfaces as a high school student and the bass player for the popular band Silent Black Kitty, but he initially acts cold and distant toward Nino. This behavior is a deliberate attempt to protect her from the complications of his own family troubles, which he prefers to handle alone. Beneath his harsh exterior, he genuinely cares for Nino and still cherishes their shared past. Momo is introspective, often keeping to himself, yet he occasionally reveals a lighter side through corny puns that surprise those around him. He and Kanade Yuzuriha become rivals both in music and in their feelings for Nino, though Momo holds a deep respect and fondness for Yuzu. Throughout the series, Momo struggles with his conflicting desires to reconnect with Nino while shielding her from his personal struggles, prompting a gradual journey of opening up and confronting his own emotional barriers. His notable abilities include his skill as a bassist and his talent for songwriting, which he uses under the alias Momo Kiryuu while working in the music industry. Key relationships define his arc: his unresolved love for Nino, his competitive yet affectionate dynamic with Yuzu, and the lingering impact of his family's pressure on his choices. Over time, Momo develops from a guarded, emotionally withdrawn figure into someone more willing to let others in, learning that genuine connection cannot be sustained through avoidance alone.