This World with You - Genmui (Genya x Muichiro Fanfiction)

*Ignore the trashy cover that I drew last minute with little to no motivation*

In a world where Natural Disasters were prone to happen, two survivors find themselves meeting. From strangers, to enemies, the two must find their true friends and survive this dying planet.
A young boy named Muichiro is forced away from his family when a tornado hits his home town in the summer. He miraculously survives, but is forced to survive on his own. He's overwhelmed and alone, his only shelter being the ruins of his once-called home.
A different young boy, undergoing a similar situation, named Genya finds himself stuck in his house with two of his younger siblings. He is trying his best to keep all of them alive, including himself. His parents and remaining siblings were forced to retreat, so he is now responsible for his siblings Sumi and Koto.
What happens when the two meet and survive together? Will they perish in the wild storms of the Earth? Or will they make it to a safe place, and be reunited with their families?