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brightness; luminance; cheerfulness
明るあかるさを上げようあげよう。
Let's increase the brightness.
部屋へや全体ぜんたいの明るあかるさが足りたりない。
The brightness of the entire room is insufficient.
彼女かのじょは持ち前もちまえの明るあかるさで人気にんきだ。
She is popular due to her natural cheerfulness.