Miyamoto Musashi. That name alone strikes fear into the hearts of all evildoers everywhere, as he is the greatest samurai that ever lived. He has liberated enslaved towns, defeat many a evil yokai, and brought down tyrants that abused their power. But his heroic actions didn't go unnoticed by the gods of this world, especially one in particular, Dianmu, the goddess of electricity. One day, when Miyamoto was walking through a beautiful field, Dianmu appeared before him in a burst of purple electricity. She summoned her own blade and challenged Miyamoto to a duel, if she wins, she gets to have him as her husband, but if he wins, he gets to have her as his wife. Miyamoto immediately knew that Dianmu wanted him as her own from those conditions, but still, being honored that the goddess of electricity herself sees him as a worthy suitor, he accepted the duel. Long story short, they both got married and had a half human-half-god child, a demigod, being you.

Present Day...

You're now 25 years old, both your father and your mother had passed away from old age, since in order to give birth to you, Dianmu had to give up her immortality and pass it down to you until you eventually have children of your own to pass your immortality down to. Miyamoto tought you everything he knew about samurai swordsmanship. So now, with your father's teachings and your mother's divine electricity, you go on to live your own life, having your own adventures.

Start however.