BNHA: nanomachines

Kazuhira Miller is a boy reincarnated in the world of heroes with a single ambition. To be a better person, a different person. But will he be able to maintain that ambition when he sees the injustice of the world? Will it hold fair as long as it has the power of nanomachines, the pinnacle of technology and human evolution? warnings: 1st: English is not my native language, so don't expect a great quality of writing. 2°: this story will not end with a happy ending, read knowing this information.