"Boss-san" (as Piro sometimes calls him) and co-worker Erika have an unusual relationship that goes well beyond manager and worker. The easy rapport between the two hints at a much deeper mystery as to how they know each other so well. Also, Yanagisawa lets Erika rattle him with simple looks, prompting him to hire Piro on the spot and later allow him and Largo to move into the old apartment above the store. He explains that her look 'gives me the shivers'. It is apparent that he has known Erika for 'a looong time'.
There is conjecture that Yanagisawa "took-in" Erika after she quit her work on Girl Phase and went into an emotional tailspin, providing refuge in her time of need. Whatever the case, while Yanagisawa teasingly calls Erika a "big pain in the butt", it seems clear that he not only knows many details of her past, but cares about her continued well being.
Otherwise he is a considerate and savvy person, offering advice and "motivation" to others when he thinks it is needed.
He is, in a way, the stereotypical old, wise and smoking character found in some animes/mangas. One such character is Bunta from Initial D; Haruka from Love Hina is another example, interesting because Fred has paid homage to (or been accused of 'stealing' from) Love Hina.