Yes, the picture drama tells us about a box of sweets.
Short summary: The box of sweets was given by Natsume and there’s a secret compartment in it. There, it stores a microfilm still undeveloped. But no thanks to Fuuran’s antics and curiosity, the film was exposed to sunlight and eventually destroyed. But Yukina doesn’t mind because what’s on that film is a secret :3
There’s a lot of funny stuff here. Aoi figures Kazura’s favorite food which made the latter embarrassed (gah, you’re such a cute couple). Fuuran’s curiosity on how to use the telephone made a little confusion to Yukina and Natsume. (LOL, Aoi=monkey, Kazura=hound) Natsume’s comment on Yukina’s beauty marks and a lot more.
BTW, here are the scans from Vol. 7
Sakurai Kikan, assemble!
Kazura still looks cute in a trenchcoat
Now this is one awesome wallpaper
That’s all. Finally, the series just ended. I’ve read in someone’s post that he wished for a movie sequel with a Casablanca-like plot where Kazura and Yukina would reunite and that Yukina would be wearing a real Chinese dress. But that’s unlikely going to happen since the period of this show is set in a very controversial era. I hope there are more spy action (not necessarily with superpowers or cybernetics) anime out there.
Also, those who were planning to watch this series, be sure that to read any Asian history book (accurate at least) that pertains events of pre-World War II. Or research any pre-World War II event in Asia.