My Childhood Sweetheart Is Actually a Mecha Warrior

[Mecha+girl+city+high martial arts+love+tsundere+funny] My name is Chen Qingyan, an ordinary high school student. The only special thing is that I have a black and straight childhood sweetheart named Gu Shuangyue who I grew up with. She is very beautiful, but she is cold, cruel to me, and has a sharp tongue. Life seemed very peaceful, but I gradually discovered some secrets of this world. The black gilded mecha has abilities beyond imagination. Gu Shuangyue's strange behavior, the strange creature hiding in the dark. The mysterious CPA organization, a university that teaches mecha. Even the blonde princess from England, with a tragic fate. Everything seems to be telling the hidden secrets of this world. Until one day, that piece of black metal quietly grew out of his spine. Chen Qingyan stood on top of the world, opening her arms against the strong wind, dancing with laughter and thunder and lightning. "O ancient demon king! Please listen to my call!"