Kawaii Deco Swap (QUICK)

I'm sorry, what is a deco book?? I know this must be a stupid question, is it just a note book?

Hello! Check here: http://blog.swap-bot.com/swap-craft-term-glossary/

Decos – A deco is similar to a friendship book and there are a wide variety of types. It is a bound book of pages which are sent around the world. The person that the book is “for” is usually listed on the cover and when the book becomes full it is sent back to them. Each person that receives and signs the deco will decorate one page according to the theme of the booklet (if there is one) and put their postal/email address and sign their name. Typically, each entrant in the “deco” must use one full page to express themselves. Glitter, sequins, feathers and other scrapbooking supplies are frequently used in “decos.” Despite the artistic expressions used in these types of friendship books, the basic rules of passing the friendship book to person to person is the same.

how many pages do we decorate? and does it come back to us?

Sure you can make it for yourself. Just decorate the cover if you're making it or one page if it's been passed on to you.