Kuchibiru kara Ai

Riku, a beloved handyman known throughout the town, struggles with crowds due to his sensitive ears. After failing his entrance exams for that very reason, the one who supported him was his high school friend, Sumiharu. Despite being busy running his own business, Riku found comfort in Sumiharu's companionship. However, one day, during an ordinary phone call, Riku unexpectedly felt aroused just from hearing Sumiharu's voice. Confused by this sudden change in his feelings, Riku begins to notice that the physical closeness between him and Sumiharu is steadily increasing. What could this mean for their relationship?

(Source: Frontier Works, translated)