相手 is a character named "Shirogane" who is a young hero from a planet called "Kamihoshi" and possesses a special sword called "Shinsei-ken". She used to lose to various enemies and was laughed at, but never gave up and worked hard to improve. Shirogane has now become unbeatable thanks to her determination, relentless training, and her resolution to never lose anything important ever again. She is calm and collected but resolute and will protect her friends no matter what. Shirogane's skill involves recalling all of her memories, including losing streaks, first victories, winning tournaments and conquering difficult dungeons, which motivates her to fight harder and avoid any mistakes. In the battle against あなた, Shirogane successfully avoids all of あなた's attacks and lands a decisive blow with her Shinsei-ken, declaring that she will never lose anything important again. [Endindex]