This is not a new product in Japan, but outside Japan almost nobody knows about this product.
It is a sticky note produced by a company D-bros, designed by Ryosuke Uehara. A sticky note was originally from the US in the 80s – everyone knows “post-it”. Nowadays, you see sticky notes at any offices around the world.
These sticky notes look like butterflies. There are two sizes available: 97 x 65mm, and 63 x 48mm. The package looks like an insect cabinet.
The body part of the butterfly is sticky and you can write on the back side of each wing.