These phone charms are rather adorable.
They are 'chibi' styles for modern Sonic, Tails & Amy. However, the way they're drawn, it looks like the charm loop is pulling part of the character. Little Sonic & Tails look surprised (he's held up by a spike tip, Tails is by his tails) while little Amy has a hand up going 'uh oh' as the back/collar of her dress is pulled to hang the charm.

They sort of play upon the "paperchildren" concept where something is drawn/made so that it looks like its interacting with the world around it. These are supposed to be made for TGS2013 in Japan by Cospa, but so far, they are only little drawings you see here. If they get made, they'll be around 630 yen, which is about 6 dollars each. These are made of flat rubber, & seen on Japan Keychains 3.