Uroshima Monogatari Manga

うろしま物語 ; A Journey to Uroshima ; Der Casanova Komplex ; Voyage à Uroshima (French)

A man suddenly gets off the train at some rural station, and soon comes to realize that this town can't be found on any map. Even stranger are the manners of Urushima's townspeople - because over there people are doing it openly on the street, in broad daylight, just like you'd say "hello" to somebody elsewhere. And there are many other things being weird about this little town Urushima, seasons are randomly coming and going, and our protagonist meets the woman of his life. Shouldn't be hard to get her given the prevalent manners...