If you're looking for manga similar to Tokage Shufu. Hoshikui Dragon to Chikyuu Gohan (Light Novel), you might like these titles.
The evil dragon who was the enemy of humans turns into a helper after several thousand years!? That was a story of the past, when magic was still a fundamental part of the world. At the end of a battle with the Hero, the strongest dragon was sealed along with his allies. The name of that dragon who ruled over vast races of magical beasts was Nielfeld. And several thousand years later—what he finds after the seal was broken by the descendant of the Hero, Patricia, was a world where magic had fallen out of use and science dominates! Introduced to the human society by Patricia, Nielfeld and his allies helps the humans out from the shadows!?
A totally normal high schooler whose only good point is his toughness, Tetsu. The lizard he happened to pick up one day, turns out to be a super rare dragon!? Not knowing how to raise his dragon, he turns to the internet. However, his walk with his super rare dragon is a trending topic. What kind of insane turmoil will this bring into his life...?
Melissa, an attendant-in-training at the royal castle, wants to work beside the Dragon Knight's commanding officer Hubert, a man she admires, and the dragons which she loves. However, she suddenly finds out that he has retired and left the castle!