His love for Ran has never been a surprise.
It's not like his friendship with Hattori (he honestly still can't say for sure which of them was more surprised by that, though obviously Hattori would insist on denying it) and certainly nothing like what hangs between him and Sera, which has continued to prove undefinable since the shitstorm and a half that she and hers mostly-intentionally wrought upon them.
So – no, his feelings didn't come out of left field, unless that included some kind of two-decades-and-counting glacial creep. But sometimes the depth of it all still takes his breath away.
Like it has right now, however ridiculous he might look standing in the doorway of their (!) kitchen and staring at his wife (!).
Ran lets out a little eep when she turns away from the stove and spots him there, though of course the pot in her hands doesn't even tip. She's always been far too steady for that. "Shinichi! How long have you been standing there – what are you even doing?!"
"Wondering what a certain mystery otaku ever did to deserve you," he says with a cheeky grin, though at least he waits for her to finish transferring the udon into two matching bowls before moving around the counter for a kiss.
Still, Ran prods him with the handle of her spatula when they break apart. "I don't know, you tell me. Or better yet, tell me while you're bringing these over to the dining table."
"Well, I hear he's actually pretty good at mysteries. Rakishly handsome, to boot," he adds just because, and Ran snorts even as he shakes his head. "But after all those things that I hid from you – "
" – which I think we've agreed was a foolish thing to do – "
" – which was unwise of me, yes," Shinichi agrees, before he catches sight of the glint in Ran's eyes and the rest of whatever he'd meant to say leaves his head in a rush. "And I guess rakish is really more Hattori's thing than mine?" he hazards.
"I love you too," Ran answers, and pecks him on the cheek. "Now can we sit down before the food gets cold?"