"Beako" should probably be "B-ko". Naming girls "A-ko, B-ko, C-ko" is kind of a running gag, similar to how you'd point to a group of people as "Tom, Dick, and Harry" in English (or "Huey, Dewey, and Louie" for Americans).
That should probably be "Castella-Kun" rather than 'Portugese cake'. Whilst Castella is derived from imported recipes, it's a Japanese cake. It'd be as odd as calling Ramen "Chinese noodles" - historically correct but worthless as a description.
Scientifically Accurate Spider Wife: spiker silk has not only been used for centuries as a thread for wound sutures, but spider silk (And silk derived Firoin) has been used as a protein scaffold for bone tissue culturing and regeneration.
Or the much simpler explanation: The PRC spies are Japanese citizens that have been turned, just like most spies. Easiest way to get plants to the other side of the gate would be to have them posted there under official business as Japanese citizens. They talk to themselves and others in...
The obvious loophole in the confidentiality contract is that it only covers items other than those gifted to them. So picking items that are themselves evidence - that are then gifted to them - are unfettered by the contract.
I'd laugh at hackerman there wielding an IBM Model M keyboard, but you could literally beat someone to death with one of those things so I guess it works.