Asuka of the Scarlet Sky

Kashiwagi Yuuto, who was bored with his life, dies in an unexpected accident. In the afterlife, the gods grant his wish to live in another world, and he is given the ability to craft divine artifacts. When Yuuto is thrown into the new world, he is confronted by a giant dragon, but he is able to defeat it with a single blow of his improvised sword. That was when he meets Asuka, a girl who aspires to become a swordsman. The story of a master crafter and an apprentice swordsman who will become a hero! (Source: Frontier Works, translated)