who are Mouschi and boche? what does boche's name mean?

Mouschi was Peter's cat, a male. Miep Gies described him as a "spritely, lean black tomcat, very, very friendly." apparently Miep looked after Mouschi after the raid. Finally an office cleaner took him in at her home.

Moffie or "Boche" was the male warehouse cat. Miep Gies described him as a, "big, fat black-and-white tomcat with a slightly battered face." Boche is what the French called the Germans in WWI.