thunder breathing can be obtained by talking with Kujima, he lives in a house in the coast forest next to the okuiya river/bridge.
his first task is for you to give him 20 soup, this will cost you 400 yen.
his second task is for you to bring a 'confidential letter' to marrone.
after he will ask you for a crazy number of 4000 yen. so before you try to get this breathing save up some money first, cuz you WILL be broke after thunder breathing.
Heat Lightning
after paying him he teaches you the first skill: thunderclap and flash.
SixFold
breathing passive: more stun on attacks
Thunder Swarm
first skill, thunder clap and flash: the user dashes forwards at lightning speeds hitting the opponent.
second skill, rice spirit: the user dashes 5 times around the opponent at amazing speeds.
third skill, thunder swarm: the user generates dashes in all directions of the opponent
fourth skill, Six fold: a improved version of the first form, the user does 5 dashes before ending it with a powerful strike.
ThunderClap And Flash
fifth skill heat lightning: lightning focussed in a single slash.