>>536131516
All I can find is this T-shirt, which according to TinEye used to be sold on AliExpress.

>>536131852
This blue variant also appeared on TinEye, in the form of a sticker sold on TeePublic. It's

It's possible these pictures were once printed on genuine Japanese t-shirts, either in the lead-up to the game's release or in celebration of it. Could also be promo art that has since been borrowed by fan-artists to sell goods. I'll see if I can find out more.