Ever heard of Kawanon lenses?

A mate has loaned me this Kawanon 105mm f2.8 and a Takumar 28mm f3.5. Now I have 5 lenses to play with.  Picked up a new roll of film, colour this time. It will be most interesting to see what that 105 can do, it has 13 aperture blades with a dimple shape to them!!