rui was trained alone by his father since he was able to hold a sword but training was tough and painful till his father introduced him to tsukasa whos father was good friend to rui's father as they trained together it didnt feel painful or tiring to train anymore since tsukasa was by his side,to rui,tsukasa saved him

But when they became adults everything changed due to his family tsukasa became the lord of his household and became corrupted by his father as he started treating others horribly but rui couldnt stand by and watch tsukasa become corrupted as rui started training harder till he walked into the tenmahouse hold and faced tsukasa with his sword in hand pointing his katana at tsukasa as sat on the floor looking at rui with evil smile on his face

"I,rui kamishiro,here by declares a dual!"