Dear Demon King

An island of gemstones and magical beasts floats in the sky...
On this island lives a kind and powerful demon king, Kougyoku.
Some forty years ago, Kougyoku used his magic to restore a stillborn griffin egg to life, and that griffin became his dearest companion, Topaz. In the years that followed, Topaz found that his love for Kougyoku had grown into something deeper than that of a beast's love for his king... and unbeknownst to him, Kougyoku had begun to feel the same.
Now, as Kougyoku struggles to summon the magic needed to restore his island, he is torn between his love for Topaz and his duty as king. And as his beloved finds himself faced with an impossible decision, Topaz is left with no choice but to decide their fates for him, even should it break his king's heart...!
Content Warnings: explicit sexual content, fantasy age gap, mild fantasy violence