Ten-kun wa Mada Kotae wo Shiranai

Ten, a postdoctoral researcher, and Tomoharu, a fourth-year university student and a team member of the same lab, clash so much to the point that it puts the people around them on edge... It's just a pretense, though. In reality, despite their age difference, they were childhood friends. Tomoharu has loved Ten since childhood and calls him "Ten-kun" and even goes as far as to follow him to the same university. Because of Ten's love for his research, he has no time to respond to Tomoharu's approach. But Tomoharu himself is not expecting Ten to say, "I don't think he'll turn his back on me..."?

(Source: Kadokawa, translated)