Dagashi Kashi
Decided to read this one on a whim actually. I have seen both seasons of anime beforehand, so I knew what I was getting into.
Absolute peak of a character design, in fact, that's the only real thing that carried the entire manga. The chapters are really short, between 8 and 15 pages on average, so there aren't much space for anything but a single skit, where the punchline often gets lost in translation or requires a 5 page essay to explain it. The story chapters are few and far between and the plot itself isn't overarching, relationship between characters basically do not develop at all.
But here's the kicker: all those things are good actually. It creates a very specific type of reading experience - it gives you that bittersweet feeling of timelessness.