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as a matter of fact; by the way; to tell you the truth; to be honest; frankly
実は、来週引っ越す予定なんですよ。
Actually, I'm moving tomorrow.
実はこれが初めての経験です。
To be honest, this is my first experience.
彼は実は日本人ではありません。
As a matter of fact, he is not Japanese.