The manga is about your typical overworked guy in his late 30s who often sees a particular high school girl while waiting for the train. Every time he notices something about her—whether it’s her makeup, clothes, cute accessories, etc.—he analyzes how it aligns with current trends among young people, how trendy that thing was when he was young, or both. Afterward, the protagonist usually reflects on his past or present and makes small changes, either by adjusting his attitude, daily routine, or something similar. It’s a very nice, cute manga that is essentially an anti-male-gaze type of story because the main character never looks at thegirl in a sexual way.

He also often jumps to conclusions when analyzing her (the biggest one being that he assumes she's a girl, when in reality, it’s a crossdressing boy), which works as a little joke, because at the end of each chapter, we usually get to see what the "girl" does or thinks about something the protagonist has overanalyzed.

It’s also a story-per-chapter manga, so there’s no need to follow it religiously every time it gets released. You can take a four-month break and still not forget too much or feel confused about what’s happening.