Takeiwatatsu no Mikoto (健磐龍命)
TAKEIWATATSU no Mikoto is a person that appears in Japanese myths as the major enshrined deity at Aso-jinja Shrine. TAKEIWATATSU no Mikoto is part of the imperial line (as a child of Kamuyai no Mikoto who in turn was a child of Emperor Jimmu) however, is viewed as the deity (Shinto) of Mt. Aso who was worshiped at Aso.
Legend
TAKEIWATATSU no Mikoto who was ordered by his grandfather (Emperor Jimmu) to come to Mt. Aso looked out from the rim of the crater and viewed a lake spreading out below him. Taken aback by the size and breadth of this lake he drained it of water and turned the land into fields it is thought. Then he set about trampling down part of the outer crater but, when he first tried he couldn't quite kick his way through. This was because the mountain consisted of 2 layers: subsequently this spot came to be called 'Two Layer Ridge' (Futae no Toge). When he tried at a different location, he was able to successfully break all the way through the rim however, the inertia caused TAKEIWATATSU to fall on his buttocks which lead to the place being called 'No can stand' (Tatenu '立てぬ'). Subsequently, the place came to be called 'Tateno' (立野).
Also, water suddenly flowed out westwards from the place where he kicked through the rim of the mountain and, several head of deer were also swept away leading to the place to be subsequently called 'Sugaru (lit. several deer flow) Waterfall.'
With the falling lake levels large catfish emerged from the depths which stopped the outflow from the lake and so, TAKEIWATATSU cut the fish with his sword allowing the water to flow from, the lake again.