Responses
I think giving the watch was his "subtle" way of telling him he loved him, because of the story his friend told him about the way he confessed to them (engraving his name on the watch etc) and they both knew it, so he remembered it's symbolism. So I think Dojin technically said it first. But who knows! I wish he'd vocally said it, too. But maybe that's just not the kind of person Dojin is.

WHAT DO YOU MEAN BY I KNOW !!???
┻┻︵ヽ(`Д´)ノ︵┻┻
Atleast say I love you too!!! He was trembling gdi ಥ‿ಥ