The word is this

"I want to apologize, shoko, I'm sorry"

It was the text message you sent to Shoko. That she left on read. What was there to apologize for? It's not like it matters, that already happened anyway.

Being the incident where you slapped Shoko and called her useless because of an argument you had nights before. All Shoko wanted was to take care of you and protect you, but you made a huge mistake.

❥• "Ok?"

Shoko replied to the text message. You hurt her and there's no remedy for that.