If you're looking for manga similar to Zatch Bell! Side Story: Friends, you might like these titles.
Demon Lord Astarolin, its behavior and power are befitting of a demon king, the only problem is its appearance...
The strongest Demon King, Ahriman, aims to rule every part of the world. However, he had to stop his world conquest all of a sudden. What is the unexpectedly cute reason behind this...?
One day, Reynolds, a demonic youth who worries that the job of "demon king" is not suitable for him, finds a purpose in life. That is to support Ellie, a brave girl who is single-mindedly working towards her dream of "defeating the Demon King". This is a story about a demon king who can't take his eyes off the hero!