Tu Si Hu Bei (The Fox Is Sad At The Death of The Hare)
Once a fox and a hare became friends with the purpose of defending themselves against their joint enemy, hunters, and swore to partake their fate for each other in weal or woe. One day as they were enjoying the natural beauty together in the fields, all of a sudden, a party of hunters came and the hare was instantly shot dead. The fox had a narrow escape. After the hunters had gone, the fox came and wept over the death of his mate.
An elderly gentleman who happened to pass by was surprised at the scene. Curiously, he asked the fox the reason of her bitter weeping.
The fox sorrowfully replied: "We are small animals and being the prey of hunters had planned to defend ourselves against our joint enemy, hunters, promising to partake our fate for each others in weal or woe. Now our enemy has killed my companion his death may mean the death of me tomorrow. We are real friends and real friends must share everything. How could I not help weeping!"
The idiom "The fox is sad at the death of the hare" comes for the story above, illustrating one feels sad for the death or misfortunes of his companions.