Why do we add 'san' to directions?

For long-time residents of Kumamoto and locals, it is so common that it is almost never a topic of conversation, but in the Kumamoto dialect, directions are sometimes referred to with the suffix 'san'.

Migi-san (Mr. Right)
Hidari-san (Mr. Left)

It is not because there are many people with the surnames Right or Left living there.

To a taxi driver,
'Please go right'
becomes
'Go Migi-san' (Kumamoto dialect).

To Nishi-san (Mr. West),
'What are you going to do by going west?'
becomes
'What are you going to do by going Nishi-san?' (Kumamoto dialect).

By the way, Kumamoto Prefecture is famous for having many decorated burial mounds. Of the approximately 700 in the country, more than 200 are in Kumamoto, and many of them are concentrated in the Kikuchi River basin. This is thought to suggest that a unique cultural sphere, different from the Yamato regime, existed in northern Kyushu, centered on Kumamoto.
In particular, because materials for red pigment (bengala) were easily accessible, they are highly regarded for their vivid colors, geometric patterns, and animal motifs.

Among such decorated burial mounds, there is one that stands out.

It is the 'Chibusan Kofun'. It is known as the 'God of Breasts' and is famous for its concentric circular patterns that look like breasts.

Did 'breast' burial mound become corrupted to 'Chibusan' burial mound?

This Chibusan Kofun is a nationally designated historic site built at the southern end of the Hiraogi district in Yamaga City.

Was it this spring that I received an offer to give a lecture from an influential person in that Hiraogi district?
The other day, I received a follow-up request.
A 70-minute lecture on February 19th, after the new year.

'Hiraogi-san ikan yan'

It is not '👴san🦑😻'.

It means 'I have to go to Hiraogi'.

I intend to take the lecture seriously.