I think this term has not been generalized enough among anime fans, but at least for the fans of the certain idol group which consists of five female seiyus, it got settled somehow…The certain idol group is, yes, Aice5 by Yui Horie, Akemi Kanda, Masumi Asano, Chiaki Takahashi, Madoka Kimura. A friend of mine is a crazy fan of the group, especially Yui Horie and Madoka Kimura. He then says, Chiaki(the left girl in above image) is what’s called, ツンドラ[tsundora] among the fans. When I heard of this term, I thought it is spin-off -ツンデレ[tsundere]…but actually no. This means the tundra…the large flat areas of land in the north of Russia, Canada etc., where it is very cold and there are no trees. At any rate, we Japanese say 寒い[samui "cold, freezing"] not only to mean it’s cold, but also to ridicule not very funny jokes. I have never seen Chiaki, but everytime she tries to be funny, it doesn’t go well so badly most of the time. But for fans of her, it is even a good 萌え[moe] point…Her jokes is extremely boring(as 寒いas the tundra), so this term, ツンドラ came up.
So, ツンドラ means to freeze the atmosphere with a boring joke, or a person who does something like this. Have you ever seen an icy gust of wind blowing just after someone failed to make it funny with a joke in manga or anime? That sort of thing.
Speaking of freezing the atmosphere, I thought it is a synonym for 電波系[dempakei; see my previous post about this, please]. Having said that, 電波系 does not seem to have the intention to make everybody else laugh though they freeze the atmosphere. Meanwhile, ツンドラ系 seems to try to make us laugh on purpose…and fails. So, it has nothing to do with 電波系.
There’s one synonym for this; サムカワ[samukawa]. Know this is an abbreviation of 寒くてかわいい[samukute kawaii,"cold and cute"]. Even though she is so cute, she is not funny at all…such a girl could be サムカワ. I think there is this type of person in the real world, but is there any in anime or manga?