Why does Mount Fuji appear slightly different in shape when viewed from different directions, such as the Shizuoka side and the Yamanashi side?

Hello! That's an excellent question, something many people wonder about.

Simply put, it's like looking at someone's face – a front view and a side profile will definitely look different. Mount Fuji is the same way, because it is not a mathematically perfect symmetrical cone. It's a living, natural mountain shaped by wind, rain, snow, and volcanic eruptions, leaving behind numerous distinctive "markers".

When viewed from different angles, we see different "markers", making the shape of the mountain appear distinct. Here are the main reasons:

1. The Biggest "Marker": Eruption Crater from the Hōei Eruption

This is the primary reason for the visual difference.

Over three hundred years ago (1707), Mount Fuji experienced a massive eruption called the "Hōei Eruption".
This eruption blasted a massive crater (Hōei Crater) into the southeast flank of the mountain, also piling up a secondary cone (Hōei-zan) beside it.
This large "dent" and the small "bump" beside it are located precisely on the Shizuoka Prefecture side. Therefore, when you view Mount Fuji from Shizuoka, especially from the southeast, you can clearly see how the ridge line is disrupted here, creating a distinctly irregular shape.

(Illustration: View from Shizuoka side shows the "gap" of the Hōei Crater)

2. The "Standard Portrait" Angle: Yamanashi Prefecture Side

So why is the Mount Fuji in our collective memory, and on so many postcards, perfectly symmetrical?

Because those "standard portraits" are mostly taken from Yamanashi Prefecture side.
Yamanashi Prefecture is on the north side of Mount Fuji. When viewed from the north, the Hōei Crater and Hōei-zan mentioned above are perfectly obscured by the mountain's own massive bulk!
So, from places like Kawaguchiko or Yamanakako in Yamanashi, no major "markers" disrupt the contour in your line of sight. Mount Fuji presents its most classic, smoothest, most aesthetically pleasing isosceles triangle shape you imagine.

(Illustration: View from Yamanashi side - Hōei Crater is hidden, contour is perfectly smooth)

3. Another "Scar": The Osawa Collapse on the West Side

Besides the Hōei Crater, Mount Fuji has another huge "scar" called the "Osawa Collapse" (Osawakudare).

This is a large erosional gully on the west side of Mount Fuji, formed by continuous weathering from wind, rain, and snowmelt. It resembles a massive crack extending down from near the summit and is still growing larger.
If you look out the window on the Shinkansen traveling from Tokyo towards Nagoya or Osaka near Shizuoka Station, you can see this huge "scar" very clearly on the western slope.

To Summarize:

Think of it simply like this:

Viewed from Yamanashi side (North): This is Mount Fuji's "flattering angle". No major flaws are visible, the lines are smooth and symmetrical – its "perfect textbook image".
Viewed from Shizuoka side (Southeast): You can see the big "dimple" of the Hōei Crater, creating a distinct asymmetry. This reveals its more "story-rich" side.
Viewed from the West (e.g., from the Shinkansen): You can see the massive "scar" of the Osawa Collapse, feeling the raw power of nature.

Mount Fuji is like a three-dimensional artwork, each viewpoint offering its unique appearance and story. Next time you see Mount Fuji, you can guess your approximate location based on its shape!