In Tokyo-centered way of thinking, it is common to divide Japan into West Japan, Kanto & Tohoku (North West East Japan). End of the game. So, no South in there (except when referring to Okinawa, perhaps).

It is true, though, that lists of regions/prefectures are almost always provided from Northern areas to Southern ones (or vice-versa), so there is a hint of South there.
In any case, since Shikoku has entered the 'South Honshu' discussion, I would like to stress the pertinence of it being featured here. It is, indeed, a lesser-known area and it is, indeed, worth exploring.

The big cities (prefectural capitals) are not particularly interesting, in my opinion, but what lies beyond them is:

- Exploring Kagawa while looking for the best Sanuki Udon joints is fun. The 'Eastern' Seto Islands (including Shodoshima, not so Awajishima) are lovely.
- Forgetting about the buzz of city-life at the shores of the Shimanto or Nyodo Rivers (Kochi) is refreshing.
- Diving in Ainan-cho (Ehime) is a once-in-a-lifetime experience.
- Climbing Mt. Ishizuchi (Ehime, tallest mountain in West Japan) or cycling along the Shimanami Kaido (Ehime-Hiroshima) are probably two of the 'hottest' outdoor activities right now in Japan.
- Finally, wandering the Nanyo Region (Ehime, Uchiko-Ozu-Yawathama area) gives you the impression of coming to terms with Japan and many of the excesses that 'modern times' have brought to this land and culture.