This is only a semi-modern shirt, probably from around the start of Sonic X airing in the USA. It may look like an early effort by TopHeavy (resembles their style) but it is by the more obscure company "Happy Kids" which didn't end up going as far as TopHeavy did. This has 3 Sonic X poses for Shadow, Sonic & an unusual one for Knuckles (both fists raised) all with yellow background squares. It's also a long-sleeve which wasn't super common either. Likely kid-size only.