A theme of transformation is likely. Losing one's heart could lead to a complete transformation into something monstrous or unrecognizable. This change from a normal state to a horror - inducing state can be a powerful theme, showing how far a person can fall when they lose an essential part of themselves like their heart.
One possible theme could be loss. Since the title mentions 'lost hearts', it might be about the loss of something precious like love, hope or identity. Another theme could be the Filipino experience, which could include cultural elements, family values, or the impact of society on individuals.
The 'lost hearts horror story' might be about the loss of something precious, like souls or emotions, which creates a terrifying atmosphere. It could involve characters who have lost their hearts in a metaphorical sense, perhaps due to some dark force or a series of tragic events. For example, it might be about a person who made a deal with the devil and lost their humanity, symbolized by their heart.
One possible theme could be leadership. If it's about a person named the 'king of hearts', his leadership style, whether it was benevolent or not, could be a theme.
Love and passion are obvious possible themes as the title has 'blazing hearts'. Another could be commitment since a love story often involves the characters' commitment to each other.
Another theme could be self - discovery. Being lost forces the boy to learn more about himself, his strengths and weaknesses. For example, he might find out that he's more resourceful than he thought when he has to build a shelter on his own. It's also a journey of growing up in a tough situation.
One possible theme could be the power of love in a big city. Tokyo is a huge metropolis, and love can be both a refuge and a source of strength in such a busy place.
Love and reluctance could be a major theme. It might be about characters who are hesitant to fall in love or admit their feelings.
One possible theme could be survival. If Phoebe is lost, she has to find ways to survive in an unfamiliar environment. Another theme might be hope. Despite being lost, she could hold onto the hope of being found or finding her way back. Also, the theme of loneliness could be present as she's on her own in the story.
Another theme might be survival. If they lost their home or financial stability, they would have to find ways to survive and start anew. They would need to look for new places to live, new jobs perhaps. It could be about how they overcame the difficulties and rebuilt their lives.
One possible theme could be survival. When children are lost, they have to figure out how to stay alive in the wild.