I cannot direct you directly to a manual, but your machine looks is close to a lot to many different batched japanese machines. We got at thread here about them, and you may find some information there:
Vintage Japanese 'Badged' Zig Zag and Straight Sew Sewing Machines
Furthermore at facebook group excist on Vintage Japanese Sewing Machines. I guess the group got about 100 manuals in their files section, and you may get lucky to find it there.