I've definitely seen that a few times in anime or manga (it definitely happens in Zettai Karen Children). Birthdays in general seem to get a lot of focus too, so I'm not sure where the idea that they aren't a big deal comes from. I suppose the difference might be that it's more likely for the person who cares so much about their birthday to go around loudly advertising the day so the opportunity to feign ignorance doesn't come up.
Or maybe they just don't like surprise parties.
edited 13th Jul '11 7:36:24 PM by Clarste
It happens in the TV series of Sakura Taisen, but it's explained by the other characters as being a result of the custom in Japan at that time for everyone to be officially a year older on New Year's Day. The birthday in question belongs to a French girl.
A True Lady's Quest - A Jojo is You!That's an old Chinese tradition, but they don't use it in modern Japan anymore. I believe Sakura Taisen is a period piece though, taking place in an Alternate History?
That's kind of a Dead Horse Trope now so I don't think it counts.

Edit: Spork Ninja'ed!
edited 13th Jul '11 7:28:39 PM by NapoleonDeCheese