Kinsoji is a relatively modern temple, not being founded until 1914. Its location is right behind the Kibune Shrine in Iizuka that was very popular with boatmen on the two river forks that run nearby and I suspect that may have had something to do with it.
No-one was home when I visited so I couldn't get inside to see the Fudo Myo enshrined there. It is known locally as Chiri Kiri Fudo, and as best as I can ascertain it was prayed to to prevent "convulsions", in this sense I think it means fits of temper by babies. It also prevented children from running awaya from home.
It was a very small temple and hard to find as it looks just like a house. The giveaway was the Fudo Myo statue outside.