Chapter 138 (Beastars)

A Transient 21,500 Years (刹那的２１５００年) is Chapter 138 of the manga Beastars written and illustrated by Paru Itagaki, published in the Weekly Shōnen Champion of the Akita Shoten publishing house.

Synopsis
On the streets of the Black Market, a carnivorous duo find themselves happily fleeing after having made a bank robbery, until they are stopped by a gigantic figure they mistake for a bear and quickly reveal that it is a multitude of mice forming the figure of a bear. The leader attacks one of the carnivores and they steal the loot from the carnivore duo, presenting themselves as The 500 Cornered Rats and flee the place.

The 500 Cornered Rats are a band of thieves made up of 500 mice whose policy is to steal from criminals. The 500 mice have memorized the entire Black Market and open society. They have a list of all the "animals who get money in bad ways", the bigger the criminal the better. The really big ones never see them coming and as petty as it sounds, robbing big animals is just plain fun. However, the boss is unexpectedly captured by a couple of policemen and despite his demands, his loyal henchmen surrender to the police in order not to abandon his boss.

The average lifespan of a mouse is 43 years, although advancements in science have prolonged the lifespans of many small animals such as rabbits, ferrets, and squirrels. It is difficult for mice to live long, with their small organs in bodies which rarely exceed 30 centimeters in height. It is only natural that they are neglected in society, so instead of living a small life as a small animal, The 500 Cornered Rats chose to live life 500-fold, proud of living 21,500 years worth of a mouse's life.

In the police interrogation room, The 500 Cornered Rats are put into a sack in which they are whipped against the wall by a policeman, who demands that they reveal where their hideout is. A colleague points out that the mice don't have a long time to live, so if he keeps hitting them, he will end up killing them. The policeman assures that the death of a group of mice will not harm anyone. However, Yahya arrives at the scene, surprising the police. He assures that all life is equal - large animals with bodies so heavy to the point of being ridiculous, small herbivores with bodies too light to be detected by automatic doors, and then there is Yahya himself. After kicking and knocking the policeman unconscious, Yahya declares that all are the same and all life is equally trifling. He alleges that it is his job to save trifling lives, taking the head of the mice and threatening him by drowning him in a glass of water. Yahya demands that they share their blacklist and their knowledge about the Black Market, and he will set them free. Despite the boss's refusal, the other mice accept by asking their boss to let them help Yahya because he isn't underestimating them or patronizing them either. He is a large animal but still has their approval, so the boss finally accepts while Yahya remains confused.

In the present, Yahya meets with The 500 Cornered Rats after 10 years of collaboration, with the head of the group already being an old man who does not have much time to live. The head of the mice claims that he has spent the last quarter of his life following him, so he knows what is on Yahya's mind, he feels lost, but the boss assures that Yahya's job is not to persistently pursue one criminal at a time, it is to keep a watchful eye and save disadvantaged animals like them. They ask why he does not ask Legoshi for help if the police cannot help him, but Yahya assures that he definitely cannot help him, and he has already canceled his contract. The boss points out that he still gave Legoshi a piece of evidence, the mask Melon wore on the night masquerade. They ask Yahya if he is actually expecting Legoshi to pursue Melon.

Characters

 * The 500 Cornered Rats
 * Inarigumi (mentioned)
 * Yahya
 * Melon (Yahya's imagination)
 * Legoshi (cameo)

Important Events

 * The past and origin of Yahya's mouse squad, The 500 Cornered Rats, is revealed.
 * It is revealed that Yahya gave Legoshi Melon's so that he could follow his trail.

Trivia

 * It is revealed that mice are a disadvantaged demographic in society. Due to their small size and short life expectancy, they tend to be ignored as a target audience when it comes to making products for daily use. In addition, their useful life is underestimated by other larger animals.