Apologize to Koichi right now!
If you apologize even though you haven't done anything wrong it makes me uncomfortable.
I feel bad that you won’t get a satisfying result, but I refuse to apologize for something I didn’t do.
This word consists of kanji with hiragana attached. Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means apologize so the verb vocab version is to apologize.
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: When you say you're sorry to apologize, you'd probably start with: "I am (あやま) sorry!"