Einlion
There is a custom/culture in Japan of not sharing an umbrella with another person unless you want to flirt called "ai ai gasai" in fact, girls tend to "forget" their umbrella to see if their crush has feelings for her, the " ai ai gasai" it is said that when it occurs reciprocally it means that they will get married in the future, in fact they also write their initials on the umbrella as Westerners would do with the trees