Omoi Tabaco wo Sutteru Fukenkousou na Toshiue Bijin to Dorodoro no Kankei ni Natteita Hanashi

This manga is an adaptation of the novel by Kametsu Tomohashi.

The protagonist is a high school boy living alone in a cheap apartment while working part-time at a convenience store. He secretly harbors special feelings for a female regular who visits the shop.

She always comes in to buy just a single pack of a specific brand of cigarettes. When he discovers that this woman is actually his next-door neighbor, the relationship between the two begins to unfold.