I can understad him thinking is just obligatory chocolate and there is no deeper meaning to it, but he knows she is the only one that notices him, who else that he thinks is going to be from.
All Najimi had to do was invite Youhei while they where in the classroom and also invite the other friend with his gf, but no, she had to do it in front of the ghost harem.
@versub she pretended to not see ghosts for 1 chapter, I don't even know what was the point of it.
My guess is that the card will be read aloud while they are still holding hands.
@LemonJuice At my school we had a similar game, but the item was announced aloud as all the teams had to look for the same item.