Shinjū

Shinjū is a Japanese word that means "double suicide". It happens when two people, often lovers, agree to die together. This might sound very sad, but it was a way for these people to show their love and loyalty to each other, especially if they couldn't be together in this life.

Now, the reason this is not done very much anymore is because it's actually very dangerous and can lead to death. Plus, there are other ways to show love and loyalty to someone without risking your life or theirs.

So even though it might seem like a very romantic thing to do, it's not a good idea and it's better to find other ways to show your feelings for someone.