An Otsuchi, in case you have not been keeping track of your traditional Japanese weapons, is a wooden maul or mallet used by Japanese warriors, primarily for bursting through doors or gates or even walls.
Mine is a 10 lb head mounted on a 3 foot shaft (apparently they could go up to 6' shaft, which would be handy for breaking into things. Not so much as a weapon). I have taken some practice swings with it and it is amazing how heavy 10 lbs can be when you are moving it through the air.
In a way, the Otsuchi describes my life: an obscure weapon with no practical purpose to be trained with simply because it can be done and I want to do it. Really true of so many of the interests and activities that I pursue.
Which is okay. Because in the end, Thor does not really exist - but I and my Otsuchi do...