Mundane: Furniture 101 (Skills come in the form of a slightly-too-rare bite of meat of unknown origin. From Jabberwocky's game.)

Information about being furniture! In Umineko, there is a type of being called "furniture," and they are generally magical beings who serve witches/wizards/etc. They're called furniture because they're basically living tools: you should use it how you like, but you're also free to break it/throw it away/get another one/etc. etc. However, because they're tools, they have pride in being used! They're technically stronger than humans, being magical, but they also can be used by humans as well.

Views on being furniture differ from furniture to furniture! You have furniture like Ronove, who carry out their position with dignity, and then you have furniture like Kanon, who are colorblind who think of it as an ultimately miserable thing. However, furniture are commonly dedicated to their duty and their masters, regardless of their attitudes toward it.

For Sakutarou, this skill is a) knowledge that he is this thing magical called furniture and b) the basic ideas behind being furniture (being used, etc.)! Sakutarou's view on being furniture is pretty unique in canon, because though he is Maria's furniture, their relationship isn't that of a master/furniture pair because Maria and Sakutarou are a little different. However, Cub won't get his canon views on being furniture back, since there's no Maria. I think it'll be interesting to see what he does with the basic principles of being furniture without Maria to influence it :3c

( quotes from ep4 about furniture! warning for mild spoilers. (i could do other eps but 4 already had a lot) )