Ichitaro
From Just Solve the File Format Problem
Ichitaro (一太郎) is a Japanese language word processor developed by Just Systems. Ichitaro dominated the market in Japan until Microsoft released Word for Windows.[1][2]
File Identification
JTD files is the extension used for the Ichitaro software. Format currently uses the "OLE2" document container format.[3]
Versions 8, 9, 10, 11 are support in LibreOffice.[4]