From AQUA Scans:
The curious prince of the mermaid kingdom, Naru, sees a human girl, Nami, and falls in love with her at first sight. Yearning for her love, he seeks a witch to turn himself into a human! But to gain this form, he has to exchange "something" in return...

On a trip to look for his brother, a hungry Hachiya Rei stops at a shrine to pray. It is just his luck that he is accused of stealing money from the shrine and forced to work to pay off the amount stolen. However, the real thief turns out to be a daemon, or a god turned evil! An encounter with the daemon unleashes Kagutsuchi, the god of fire, concealed in Rei. As Kagutsuchi's proxy, Rei can use the god's holy fire to purify daemons, but there's a side effect...

As a descendent of the famous exorcist, Abe no Seimei, Yuuichirou has always been able to see ghosts. Yuuichirou, as a child, was proud to be a son of the Seimei Shrine and wanted to follow in his father's shoes and become an exorcist until he's bullied by Ishida in elementary school. Now, as a teenager, Yuuichirou has lost his faith in Seimei. Can a visit from Abe no Seimei, himself, restore Yuuichirou's faith and close the rift between father and son?

A manga anthology based on the DMM Games/Nitroplus browser game Touken Ranbu -ONLINE-.