My suggestion is to ambush them on the way home~

If it's as you're leaving... I propose, putting it in their shoe locker

That is one of the classic ways that comes to mind~

Or instead of their shoe locker, you could put it in their desk...

Though in those cases, you don't get to see how they react...

And in the worst case, they might think it's a present from someone else

Then, how about a bold Grand Valentine Surprise Operation!

Now that would leave an impact-!

But, it might surprise them so much that your feelings wouldn't quite get across...

Right~♪

Cinderella Girls Theater

劇場第1240『チョコの渡し方』 Theater Episode 1240 - Ways to Give Chocolate