The Superpowered One's Ghost King Husband

[Synopsis] My upcoming novel, Gin Is a Beautiful Mermaid, will be starting soon. Add it to your collection if you're interested~ Because of his awful older brother, Saiki's psychic powers went berserk and he transmigrated to the Taisho era. During the Taisho era, an unconscious boy was brutally gnawed on by demons. Scumbag Demon King: Look at my shattered mouthful of teeth and say that again! Under a beautiful cherry tree, he met a kind charcoal seller. The future Flame Hashira: On that day, a god descended to the mortal world! The Demon Slayer Corps thought he was a frail boy being kept by demons. Scumbag Demon King, who kept getting his head ripped off by the "frail boy": ? The Twelve Kizuki thought he was a helpless child bound by the Demon King. Scumbag Demon King: Do all of you have something seriously wrong with you?! At last, after helping the Demon Slayer Corps successfully defeat the Demon King, Saiki returned to the modern era. Everything seemed to return to normal, and the story from the Taisho era seemed like nothing more than a distant, long journey. Until the first day of university, when he met his fated roommate. Saiki: Demon King? Scumbag Demon King (shaking his head wildly): That's not me, I've never been there, you've got the wrong person! CP: Demon King x Saiki Gin Is a Beautiful Mermaid! [Synopsis] Koumei had a childhood friend named Jin, with whom he shared his happiest memories. But when they grew up, they went their separate ways. Koumei became a police officer, while his friend... was kidnapped by an evil organization and forced to work for them! To rescue his friend, Koumei repeatedly brought up the idea of defecting with him. He talked about it at the dinner table, at bedtime, and even while Jin was taking a bath, standing outside the door and reminding him. "Thump." "Thump." "Thump." Strange sounds suddenly came from the bathroom. "Jin, is something wrong?" Worried something had happened to him, Koumei turned the handle and barged in. At a glance, he saw a strong, dark blue fish tail resting on the edge of the bathtub. "I-It's nothing!" The usually composed Jin was uncharacteristically flustered. He buried his whole head under the water, but his tail seemed to slap the tub even more excitedly. Koumei stared blankly at the scene, his eyes growing brighter and brighter with understanding. His Jin was a beautiful mermaid! - Gin first met Koumei in Nagano. He was still young then and had gone to Nagano on a trip with Karasuma. One morning, Gin was still hungry when the smell of blood drew him toward the Morofushi home. There he saw Koumei sitting on the steps, holding his younger brother. Their eyes were both vacant. Gin walked right over and, standing in the doorway, saw two bloodied corpses inside. Mermaids craved blood. The young Gin could barely stop himself from baring his fangs, but a hand covered his eyes. "Don't look." Koumei's voice trembled, but his palm was exceptionally warm. As if in a trance, Gin withdrew his fangs and obediently held back. PS: Koumei x Gin, police officer gong x mermaid shou Theme: Justice will ultimately triumph over evil