1.
tea stalk floating upright in a cup
A small piece of tea stem that floats vertically in a cup of green tea. In Japanese superstition, this is considered a sign of good luck.
茶柱が立った！
A tea stalk is floating upright!
今朝、お茶に茶柱が立っていたから、いいことがあるかも。
A tea stalk was floating upright in my tea this morning, so something good might happen.
茶柱が立つと縁起がいいと言われている。
It's said to be a good omen when a tea stalk floats upright.
The key expression is 茶柱が立つ (a tea stalk stands/floats upright). This is one of Japan's well-known everyday superstitions. The belief is that if a tea stalk floats vertically in your cup, good luck is coming. Some say you should not tell anyone about it to preserve the luck. With the shift to tea bags and bottled tea, the phenomenon has become rarer, giving the word a somewhat nostalgic quality.