Tsumu (積む) is the Japanese for "to stack" or "to pile up". Disney stacked this to the next level and came up with Tsum Tsum and created an app where one stacks Disnified cubes into a nationwide phenomenon. (That link will send you to a page where you can buy the game and tons of goods.) Almost every gal (and some guys) in the school has a Tsum Tsum pencil case or eraser or t-shirt or bag. Admittedly, these are incredibly cute and will probably next take America by storm.
This looks far more addictive than Candy Crush. I'd better not get the app!
Recently, 7-11 has come out with some seriously cute magnets that come attached to Pet Bottles of tea yet surprisingly, they aren't stackable!
Furthermore, they have now began one of those raffles to win Some Tsum Tsum merchandise. I landed a bowl but at 620 a pop, I'm going to hold off on any more of these, until they go on sale that is.
My first introduction to these characters was with some UFO Catcher cellophane tapes. I have a pal who is an avid collector of these and I managed to land an entire set for her plus several doubles for myself.