Isekai Rebuilding Project: Volume 2 by Yukika Minamino

After running wild to save the people of a fantasy world from an anachronistic beriberi epidemic, Eiji and his dragon companion Tiamat discovered the root cause of the world’s deterioration. Accompanied by Baze the Fenrir and Hieronymus the Cait Sith, they now embark on a new journey. Tagging along with the Murdock Troup, a traveling circus, they arrive at the kingdom of Noura, where Eiji and his party will face down an entirely new challenge.