I want to write a story and I want your help brainstorming ideas. Here's some backstory:
It's set in the fictional Republic of Ezo, a state composed by Hokkaido (minus the Oshima peninsula) and Southern Sakhalin. Sakhalin in particular is a melting pot of Russian, Japanese, and Ainu influences while Hokkaido is mostly Japanese (except certain Ainu-majority areas like Tokachi). The main character's (named Alexander Akulov) grandmother (Anastasia Akulova) died in a city in the island of Sakhalin, leaving him a house and a plot of land as inheritance. Since life is hard in Moscow, he moves to Sakhalin, only to find someone else living there. She claims to be his cousin. He remembers he did have an uncle and an aunt, but they were too distant from his part of the family to keep in touch with him. The woman, who calls herself Eva Akulova, says that It's unfair that he is the one who gets to inherit grandma's house but she'll press no charges for now. I also wanted something involving vampires and werewolves. I had in mind the idea that his grandma was the daughter of a Russian forced labourer (Sakhalin being a penal colony in the past) and an Ainu woman and thus she had some sort of regular interaction/relation with the predators of humanity. Queue in some artefacts made of vampire/werewolf bones that make its users immune to a vampire's suggestion/mind control and that can easily hurt supernatural creatures, both vampiric and lycanthropic. Akulov is a normal man in his 20s. He has mild interest on supernatural things but treats them as curiosities, not as things worth studying. His father was from Russian Sakhalin and his mother from Karafuto (southern Sakhalin), so he always had Karafuto as a plan B since he could immigrate due to jus sanguinis. His life in Moscow went from bad to worse after his parents' deaths: his mother died in a car accident and his father died far earlier than expected from grief. After a year working to survive and having to pay a costly rent, a letter came in the mail informing him of his grandma's death and of his inheritance. Seeing an opportunity to own his own house, he gets the paperwork done and moves to Karafuto. As for Eva, she will remain a mystery for now. All that must be known at the moment is that she resents Alexander for being chosen by her creator and for being naturally descended from grandma Anastasia. Alexander isn't too familiar with Karafuto, knowing how to speak Japanese but not to read/write it. It'll be a cultural shock moving to a remote location in another nation, even if part of its culture is Russian like his own
 Here begins the story:
Moscow closed its doors behind me as I stepped onto the platform. The frost clung to the air, biting at my hands and face, the familiar chill reminding me of the winter's death grip on the city. My life there had become a chaotic series of events. One unfortunate circumstance piled atop another, beginning with the car accident that took my mother from me, and ending with my father's rapid decline from grief. 
In the months following their deaths, I worked a series of dead-end jobs, scraping by in a crumbling apartment I could barely afford. The city had grown to feel claustrophobic, the once-familiar streets now ominous in their weight. With each passing day, the concrete walls seemed to close in a little tighter, suffocating my hope. I worked to survive.
It was on an ordinary Tuesday, drenched in bleak gray, that an unexpected letter arrived. The envelope was thin, creased from postage, and bore my grandmother's name: Anastasia Akulova. My heart raced as I tore it open, scanning the neat script within. A real estate inheritance, her house, her land, in Southern Sakhalin, or Karafuto as the Ezoans called it. The weight of my grandmother's death suddenly felt less like chains and more like wings. It was my chance, a convenient Plan B.
Two weeks later, after getting my paperwork and immigration passport done, I boarded a train that would carry me through the vast expanse of Russia to Vladivostok. The rolling landscapes outside the window morphed from the urban sprawl of Moscow to serene countryside, then bursting forests before fading into the desolate beauty of Siberia. The rhythmic clattering of the train was oddly soothing, carrying me away from the echoes of loss and towards a new beginning.
I watched as rivers sparkled beneath the weak sun, their icy banks framing the stubborn blue of the wild sky. On the train, I struck up conversations with the passengers. An elderly man nursing a thermos of tea, a family of five squished into a single compartment, their children bouncing with mischief. They shared stories of their travels, their roots, and dreams, reminding me poignantly of what I had lost. If I had any luck, perhaps some relatives still lived in Sakhalin.
As we crossed the Amur River, the landscape shifted once again. Endless steppes unfolded, a canvas of gold and green upon which many different tribes and civilisations laid their eyes. The train rattled on until finally, the buzzing city of Vladivostok came into view, a bustling blend of Russian and Asian influence that felt both foreign and familiar. I did nothing of note in Vladivostok. I rented a small room to pass the night and ate instant ramen, a situation that occurred far too often back in Moscow.
The next day found me boarding a passenger boat that chugged towards Toyohara, the capital of Karafuto and the biggest city in the island. Even so, it appeared small as the boat entered the Bay of Aniva. It was no Moscow. It could be compared to a countryside town. Not too big, not too small. As the boat docked in Toyohara, I notice the charm of the place immediately: a hybrid of Japanese and Russian culture. It had been part of Russia before and many of us settled here in the past, either voluntarily or for forced labour. My great-grandfather was among those. When Ezo gained independence from Japan, the southern half of the island was granted to them, while Russia kept the northern part. The port was bustling with activity, boats docking and departing and people, passengers and workers alike, walking from all sides. After securing a taxi, I made my way through the streets, passing colorful storefronts offering an odd array of fresh sushi and Russian pastries. My destination flickered on the horizon: my grandmother's house.
When we finally arrived, I was taken aback. The house was much larger than I had imagined, perched near the edge of a lush forest that bordered the outskirts of Toyohara. Its wooden frame was weather-worn yet stood proudly, boasting a history I had yet to uncover. Green moss clung to its sides as if nature refused to let it go. I stepped inside, the creak of the door echoing through the silence, breaking the spell of my arrival. Dust motes danced in the shifting sunlight. I moved through each room, taking in the heavy beams overhead, the faint scent of aged wood and the remnants of my grandmother's lingering presence. It felt both alien and oddly comforting, as if I was returning to a place I only knew from distant childhood memories.
As I wandered deeper into the house, I suddenly caught a flash of movement from the corner of my eye: a figure lounging on the worn sofa in the living room. I froze. The house felt too big for company to go unnoticed. Her silhouette was striking against the faded upholstery, and as I took a careful step closer, my breath caught in my throat. A woman sat sprawled across the sofa, her skin and hair an immaculate white, strikingly contrasted by the deep red of her eyes, a clear sign of albinism.
Before I could register my shock, she sat up, an expression of disdain crossing her delicate features. “You must be Alexander,” she stated, her voice low and melodic yet edged with a sharpness that sliced through the air between us. “Yes... and you are?” I managed to reply, my voice faltering in confusion. “I’m Eva. Eva Akulova,” she declared, rising with an effortless grace. “Your cousin, I suppose.” Her accent was identical to my grandmother's. Even the pitch and rhythm. “I wasn’t aware I had any… family here,” I replied, struggling to maintain composure. “Clearly,” she responded, an eyebrow arched. “But our grandma would have assured you I’d be… interesting company were she alive. For now, I won’t contest her decision regarding the house, but I want to get to know you before I consider pressing any charges. You know… if it's necessary at all.”