na-adjective, adverb, noun, noun which may take the genitive case particle 'no'
unfortunately; sorry, but ...
Expresses regret or apology when something is inconvenient or contrary to one's wishes. Often used at the beginning of a sentence to soften a refusal or bad news.
あいにく、今日は予定が入っています。
Unfortunately, I have plans today.
あいにくの雨で、ピクニックは中止になった。
The picnic was canceled due to the unfortunate rain.