Here's a whole batch of pencils dedicated to Sonic Adventure 1.
This has a metal pencil case with SA 1 theme, and a matching box of pencils that is designed like the case. Then, there are 2 more boxes of pencils with different SA1 designs. There is also a rectangle white eraser with the typical cardboard/decorative sleeve, and what appears to likely be a glue stick. Each item is themed for SA 1. It seems likely that the pencil case & set could be sold together.
As this photo is old, it is at the original size by the original owner which was the (now defunct/taken down/offline) Hikari Site in Japanese.