The aircraft in the photo is the last aircraft to cease operating in Japan on 30 September 2006, in a commemorative paint scheme.
The reason for retirement was that new safety equipment could not be fitted due to amendments to the Civil Aeronautics Act.
The side of this aircraft states.
『ありがとう日本の翼 YS-11』
The aircraft was owned by JAC(日本エアコミューター), a subsidiary of JAL, originally called JAS(日本エアシステム).
A photograph is attached at the end.
I would be very happy if they could be a good source of some information.