Japanese by Example
Learning through examples in manga

It's too late to compliment my outfit with 今更

それでも歩は寄せてくる » Volume 4 » Page 46

Ayumu heavily compliments Urushi on her looks wearing a sweater that’s a little too big. He quietly congratulates himself, and when Urushi questions him on it, Ayumu explains that he’s regretted his inability to find the words to compliment her outfit during their New Year’s shrine visit.

(あゆむ):
(いま)なら初詣(はつもうで)(とき)のもうまく()えます。どうですか」
“I can properly say it now for the New Year's shrine visit. How about it?”
うるし:
「い いいよ。 (いま)さら…!!」
“It's okay. It's too late!”

Urushi uses 今更(いまさら) to expresses her feeling that Ayumu’s compliment would be too late to be meaningful, as the appropriate moment (during the New Year’s shrine visit) has already passed.