Blessing the Japanese?

This one has puzzled me so far, so input is very welcome:

"I was going from house to house with my mother. We were giving away chocolate and blessings to each house we visited. (Don't know what the occasion was, it's not traditional.) In this street each house seemed to belong to Japanese. Each house seemed to bear a marking in red - somewhere near the entrance. On the first house it looked similar to "i+", don't remember the 2nd one, might have been "ii+", on the 3rd one it was "3+" and on the fourth one it was "4+".

I think in the 3rd house we could see through a big window that the people there were just being visited. When looking at the marking I said - maybe it's a mark people from the local Shinto shrine make? And my mother said she thinks it might have to do with the number of children (or kind of like a blessing - how many children somebody hopefully gets), but I disagreed that that did not seem like a likely explanation."

I only know that in Germany the three wise men (children in disguise) travel from door to door on the 6th of January, leaving their blessings and markings over the door (in chalk). That's why I had some feeling that this had to with the new year, vaguely.

I don't know why we were handing out chocolate, why all the people living in that street were Japanese (it did not seem to be situated in Japan) or why somebody would leave red symbolic markings on houses. On one house the mark was on a wall right of the door, it varied from house to house.

Anybody have an idea about this one?

Oliver