Here are some recommended sad anime and novels: 1. " Unheard of Flower Name ": This anime used sadness as its theme, telling a story about loss and growth. The characters in the story have experienced many sorrows and difficulties, but they try their best to find hope and reunite. 2. Clannad: This was an anime that was recognized as a tear-jerker. The story was about the emotional development of a young man and a girl who talked to herself after meeting each other, as well as the sadness and growth they experienced together. 3. April Is Your Lie: This is a healing anime, but it also has a sad plot. The story tells the story of a piano genius and a violinist. They found resonance with each other through music, but they also faced sadness and separation. 4. [When the Cicadas Cry in Cold]: This was a tragic anime that told the story of a tragic event that happened in a small village. The protagonist and the people around him were in danger, and the truth of the story was gradually revealed. 5. Nausica of the Valley of the Wind, a manga by Hayao Miyazaki, ended in tragedy. The story takes place in a destroyed world. The protagonist and a mysterious girl begin an adventure, but in the end, they face sadness and sacrifice. These recommended animes and novels all had sad plots and endings, which could bring a deep emotional experience to the audience and readers.

Another characteristic is the use of symbolism. Similar to novels, anime uses symbols to enhance the sad atmosphere. In '5 Centimeters per Second', the cherry blossoms are a symbol of the fleeting nature of love and time. The protagonist's repeated encounters with the cherry blossoms as his relationships change add to the overall sense of melancholy.
One such anime is 'Your Lie in April'. It has a melancholic undertone similar to sad novels. The story revolves around a young pianist who has lost his ability to hear the sound of his own piano playing after the death of his mother. His encounter with a violinist girl brings both beauty and heartbreak into his life.
A great sad anime story often has strong character development. For example, in 'A Silent Voice', Shoya's journey from a bully to someone seeking redemption is really moving. His relationship with Shoko, a deaf girl he once bullied, is full of complex emotions. When you see how they both grow and the pain they go through, it makes the story very sad and also very powerful.
Another great one is 'Clannad: After Story'. It shows the life of Tomoya Okazaki after high school. He has to face many difficulties in life, including the loss of his wife Nagisa during childbirth. The story is extremely sad as it portrays the harshness of life and the importance of family. It really tugs at your heartstrings.
Another is 'Clannad'. Tomoya Okazaki meets Nagisa Furukawa, and as their relationship develops, we see the story of her family, including her relationship with her parents and her sister. There are many sad elements, especially when dealing with family hardships and the challenges of sibling relationships in the face of illness and difficult family dynamics.
There were many animes that had been adapted from sad novels, such as Sword God's Domain, About My Reincarnation as a Slime, Index of Forbidden Magic Books, Gate to the Stone of Destiny, and so on. These anime works were all adapted from sad novels. By adapting the anime, the plot and characters in the novel were presented more vividly and attractive. These anime works not only had a breakthrough in the storyline, but also made a lot of efforts in character creation and emotional expression, which was deeply loved by the audience.
Anohana: The Flower We Saw That Day' is also a sad anime. Menma has died, but her spirit lingers. Her friends are haunted by her death and their past actions. They gradually come to terms with their feelings of guilt and grief as they try to help Menma move on.
They can make viewers feel a deep sense of empathy. For example, in stories like 'Anohana', when we see the siblings and friends struggle with their past and present emotions, it makes us think about our own relationships. We might have lost someone or had a difficult relationship with a sibling, and seeing it on screen makes us connect on an emotional level.
Some of the more sentimental and meaningful cartoons were as follows: 1. Your Name. (Your Name): This is an animated film directed by Makoto Shinkai. It tells the story of time and space between two young people. Through touching melodies and beautiful scenes, it portrays a profound love theme. 2 Death Note: This is a Japanese manga created by Oba Thrush, which tells the story of a talented high school student who discovers a notebook that can kill. Although the purpose of this notebook is to help people solve social problems, the protagonist uses this notebook to kill countless innocent people because of his high IQ and curiosity. This story is full of sadness and reflection. 3. Fullmetal Alchemist: This is a Japanese manga and anime created by Ishida Atsuhito that tells the story of two brothers who achieve their goals through alchemy. Although there was a huge difference between their world and the real world, this story portrayed a deep theme of friendship and kinship through the feelings and sacrifices between brothers. 4. Grave of the Fireflies: An animated film directed by Makoto Shinkai about a couple who lost their child during the war. Although they had lost their homes and loved ones, they still held on to their love and hope for the future. This story was full of touching lyrics and deep thoughts. 5. A Chinese Oddsey: This is a Japanese novel by Keigo Higashino, which tells the story of two teenagers. Although this story is full of suspense and reasoning, it also portrays a profound theme of love and human nature, making people reflect on the complexity and contradiction of human nature.
Maybe she had a heartbreak or lost someone important to her. That could be the reason for her sadness.