Ryujin/Ōwatatsumi-no-kami: God of the sea and king of all serpents and dragons, and defender of the Shinto religion who resided in the once undersea crystal palace of Ryūgū-jō. He was one of myriad of gods born from the union of Izanagi and Izanami in ancient times. Possesses an estranged relationship with his youngest daughter, Watatsuki no Yorihime.

Long ago in the past, Ryujin was a god who preferred the solitude of the ocean depths. He rarely interacted with his fellows gods that resided in heaven, only occasionally speaking with his brother, the mountain god Oyamatsumi, who resides on earth. It wasn’t until the advent of humanity that this behavior would change, as he would begin to rescue humans he’d find drowning out of pity and curiosity. At first, he simply returned them to land, but he’d eventually start taking them to his palace in the depths to be his servants. The humans, though they feared him at first, would come to revere him as their king, teacher, and god.

He eventually set his eyes on a particularly bright human girl, who he’d begin to instruct personally. She displayed such energy and enthusiasm that allowed her to brighten moods even the darkest of moods, and her sharp wit never failed to both surprise and impress him. These qualities would cause Ryujin to later fall in love with and marry her, becoming the mother of his first child, Toyotama-hime.

However, the lives of humans were tragically short. As the years went by, Ryujin would offer her means to extend her life so they may remain together forever. However, she’d refuse every time. This frustrated him to no end, but he ultimately respected her choice. It wasn’t until she was on her deathbed that she revealed the reason for her refusals:

“It is in my belief that our short lives is what makes us mortals especially beautiful, my husband. Knowing I would someday die as I should, I am able to fully appreciate the beauty of this world and the blessings it has bestowed upon me.”

Her passing would leave him devastated and her last words would leave him baffled, showing that despite his close association with mortals, he still was not able to fully understand their hearts. His grief would lead to him gradually distancing himself from his subjects and his daughter.

Many decades later, he’d eventually take a second wife, who was an ardent devotee of his. This was merely an attempt to fill the void his first wife’s passing left in him. However, it soon became apparent that he could not love her as she did him. Not even the birth of his second daughter, Tamayori-hime, would change this.

His second wife would take increasing drastic measures to earn his favor, punishing herself harshly when they bore no fruit. In her eyes, the gods were infallible, meaning the reason she could not receive his love was solely due to her inadequacies. She’d eventually take her own life via secretly poisoning herself in a last desperate attempt to gain his attention. When he showed himself at her bedside as she was dying, she was overwhelmed with such emotion that she cried tears of joy. She’d die with no regrets, her last words being an apology for not being better.
Ryujin, who was aware of her poisoning herself, could not fathom why she would go to such lengths. Having been left traumatized by this display (not that he’d acknowledge it), he would never again take another wife. This would also be what would change his mindset enough for him to ally himself with Tsukuyomi.

Possesses the ability to manipulate water, bring down lightning and cause thunder, and manipulating the winds. He can also create powerful barriers, and is known for his creation of miscellaneous magical items and medicine. Just like Tsukuyomi, he’s capable of manipulating the space within the confines of the Dragon Palace, but these powers are strongest within the Summer side that he resides in.

As both a dragon and a god, his shapeshifting capabilities are top notch, allowing him to assume a variety of forms. However, he rarely uses this ability beyond shifting between his human and dragon forms.