First of all - Another bad comic. Seriously.
Secondly - In Japan, Valentine's is when women give men chocolate, and then on White Day, men give women chocolate. Not all of it is romantic chocolate. On Valentine's Day and White Day, you're supposed to give chocolate to friends and family of the opposite sex as well (obligatory chocolate).
Thirdly - There's Black Day. Valentine's is Feb 14, White Day is March 14, Black day (where singles get together to eat some sort of bean noodle thing) is April 14th.