Kingin Sasameku Himitsu wa Yoru

Serious and formal Mikado x Alloy adored by everyone.

Alloy uses magic to support the nation's lifeline and is the active leader of the operational department. With his beauty and friendly personality, that does not take advantage of his noble lineage, he is adored by everyone around him. On the other hand, Mikado, a blank-faced workaholic does not communicate well with Alloy like everyone else. They are on opposite wavelengths. But the two are actually in a secret relationship?

(Source: Pixiv, translated)