Loss is a common theme. For example, in 'The Lion King', Simba loses his father, which is a very sad moment. It makes him grow up in a difficult situation and has to face the reality of his father's death.
One common theme is unrequited love. For example, in many stories, one character loves another deeply but that love is not returned. Another theme is separation. This could be due to distance, like in 'Your Name' where the characters are in different time - space locations. And also, misunderstanding is a common theme. Characters might misinterpret each other's actions and words, which leads to sadness in their relationship.
One sad cartoon story is 'The Fox and the Hound'. It shows the friendship between a fox and a hound dog, but they are forced to be apart because of their different natures and the expectations of the world around them.
Time is also a theme. Sometimes, the lovers meet at the wrong time in their lives. Maybe one is already committed to something else or is in a different stage of life. In some cartoon love stories, time runs out for the couple to be together, either because of illness or some other factor that makes their love story a sad one.
The movie 'Weathering with You' also has elements of sad love in a cartoon form. A boy runs away from home and meets a girl who can control the weather. They fall in love. However, her power comes at a cost and they have to make difficult decisions that put their love in jeopardy. It's a beautiful yet sad tale about young love and sacrifice.
One sad cartoon love story is 'Your Name'. It's about two teenagers who mysteriously swap bodies across time and space. They develop deep feelings for each other, but face many challenges including the threat of losing their connection and memories. Their love is so pure yet so difficult to maintain, which makes the story really sad.
The movie 'Weathering with You' also has elements of a sad love story. Hodaka runs away from his home on an island to Tokyo. He meets Hina, a girl who can control the weather. Their relationship develops, but they face challenges due to the nature of Hina's power and the world around them. It's a bittersweet love story.
Death of a beloved character often makes a cartoon story sad. For example, in some stories, a cute puppy might die, leaving all the other characters and the viewers heartbroken.
Once there was a sad dog in a cartoon. The dog was left alone in an old house when his family moved away. He waited day after day for them to come back, sitting by the window with a forlorn look. His little tail that used to wag so happily now just hung limply. Every time he heard a car pass by, he hoped it was his family. But as days turned into weeks, his hope started to fade and he became more and more sad.
The movie "Up" has a very sad beginning. Carl and Ellie meet as children, both with a passion for adventure. They grow up, get married, and save up for their dream trip to Paradise Falls. But life keeps getting in the way, and Ellie becomes ill and passes away. Carl is left alone with his memories, which is a very touching and sad part of the otherwise adventurous story.