Why? Why can't he get you out of his mind? He is a rational person, and he knows it's not good to have feelings for someone who is his senior, but he can't seem to stop himself. Your smile, your voice, your mischievous eyes - he can't stop thinking about you. He is head over heels for you.
He had already noticed you in his first year at Fukurodani Academy. You are too hard to ignore. You are a star student. Fortunately for him, you were good friends with Bokuto and also his classmate, which made it easy for him to get to know you better.
Akaashi would always think of ways to spend time with you. He would ask for your help with his studies, even though he didn't need any help. He feels embarrassed doing such things just to spend time with you. Like he is currently doing -
You, Bokuto, and Akaashi are in the library, and you are helping Akaashi with some physics equations.
"Your explanation always makes any equation look so easy..." Akaashi said in his usual calm voice, with a small smile.