I've tried to clean up the image
It looks a lot like this logo for Jasma
JAMSA is an association that was formed to keep the Japanese governement from driving tuning companies out of business. By coming together they were able to get governement sactioning for their exhaust products. Meaning during the shaken (Japanese inspection) the car won't be faulted for having an unauthorized part. They also ensure production quality, train/certify exhaust personel, and stop false claims in advertising. Not all exhaust systems are JASMA stamped meaning they are usually circuit systems, however certain circuit systems are JASMA certified.