Yes, "Maquia: When the Promised Flower Blooms" is considered a sad anime. The story revolves around Maquia, an immortal girl from a secluded tribe, who experiences profound loss and emotional turmoil as she navigates her relationships, particularly with the human boy she adopts, Ariel. The themes of love, separation, and the passage of time evoke a deep sense of melancholy. The film beautifully portrays the bittersweet nature of life and the heartache that comes with love, making it an emotionally impactful watch.

In "Maquia: When the Promised Flower Blooms," Leilia becomes pregnant after a romantic encounter with a human named a soldier from the kingdom of Mezarte. Their relationship is brief, and the pregnancy results in significant emotional turmoil for Leilia, especially as she is an immortal being. The story explores themes of love, loss, and the challenges of relationships between mortals and immortals.

At the end of "Maquia: When the Promised Flower Blooms," Maquia, an immortal Hume, faces the reality of her relationships as time passes. After a long journey of love and loss, she ultimately lets go of her son, Erial, who grows up and builds his own life, unaware of her true nature. Maquia finds peace in her memories and the bonds she formed, while Erial carries her legacy forward. The film concludes with a poignant reflection on love, time, and the bittersweet nature of existence, highlighting the enduring impact of their connection.

"Maquia: When the Promised Flower Blooms" is a visually stunning animated film that explores themes of love, loss, and the passage of time through the story of Maquia, an immortal being who raises a human child. The animation is beautifully crafted, and the emotional depth of the characters is compelling. It offers a unique perspective on relationships and the struggles of motherhood. If you appreciate heartfelt storytelling and exquisite animation, it's definitely worth watching.