5 Japanese prefectures, namely Tokushima-ken, Kouchi-ken, Ehime-ken, Kagawa-ken, and Okayama-ken, that means the whole Shikoku Island and Okayama-ken in Honshuu have been personified into 5 moe characters. The 4 mascots of the 4 prefectures of Shikoku Island have been labeled as Shikoku Moetai, which could be translated as Shikoku Moe Squad. The presence of the fifth, non-Shikoku character raises questions.
The name of Tokushima-ken’s mascot is Awa Awana. The name comes from the old name for the region, Awa.
Kouchi’s mascot called Tosa Ryou. Tosa is the old name of the region, and Ryou comes from Ryouma, which was the name of a famous historical figure from Tosa region, Sakamoto Ryouma.
Ehime mascot’s name is Iyo Ai. The first kanji in Ehime (愛媛) is usually read “ai” which means “love” and is common in names. Iyo is a city in Ehime prefecture.
Mascot of Kagawa-ken, Sanuki Kaoru. The name Kaoru derives from the first kanji of the word Kagawa (香川), which can be read as “kaoru”. Sanuki is a town near prefecture’s capital Takamatsu city as well as the old name for this region.
Okayama’s mascot is called Kibi Momo. Kibi seems to be a combination of the first kanji from Yoshii River and the first kanji from Bizen town, both of which are located to the east of the capital of Okayama prefecture, Okayama city. Okayama prefecture is famous for its peaches and “momo” means “peach” in Japanese.
People on Japanese forums have already started discussions about what seiyuu should lend their voices to these characters, despite there being no evident sign of them getting such treatment. However, if it came to it, there should be no doubt that Mizuki Nana has to be the voice of Kouchi prefecture’s mascot and Toyosaki Aki the voice of Tokushima prefecture’s one. Actually, there is a series called 47todoufuken (47 prefectures) with characters representing individual prefectures and each of them is voiced by a seiyuu who grew up in that place. You can find more about it here.
EDIT: More details about where the names came from have been added. The mistake in the first sentence has been corrected; there is no Takayama prefecture in Japan, I don’t know where I got that from orz