The large Torii along the road some distance before the shrine gives some indication of the importance of Taiso-gu locally.
A local tourist website says that Taiso Gongen arrived here from China in 724. Another source says that pre Meiji the shrines name was Jimmu Taiso Shrine. Now the main kami is listed as Izanagi.
There are another 6 kami listed here including Amaterasu, Hachiman, Sumiyoshi, & Hiyoshi, which suggest to me they were all later additions.
Like many shrines in Kyushu the grounds contained some huge Camphor trees. Taiso Shrine is well known for its Kagura, one of the few places in Fukuoka where it still exists.