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writing paper; stationery; notepaper
きれいな便箋に手紙を書いて送った。
I wrote a letter on beautiful stationery and sent it.
この便箋は花柄でとてもかわいい。
This writing paper has a floral pattern and is very cute.
便箋と封筒がセットになって売っている。
The writing paper and envelopes are sold as a set.