Kankei wa Mada Lv.1 The First Stage of Love

Synopsis

Kikuchi, a lonely bookstore clerk, can't help but wonder about Kajinoki, a regular customer of the shop. With each visit, he longs to see Kajinoki again and finds that his heart starts to beat wildly in his presence. Is Kikuchi falling in love? And isn't Kajinoki married? (Source: M-U)