Chapter 20

Alone (ひとり,) is the 20th chapter of the Kemono Jihen manga series.

Summary
Akira tries to get off the nil calculus from Yui chest. While trying to get it off, he sees his brother memories during their time together at the snow village.

At the memories, Yui and Akira is seen as young children. They are playing around where Hisame encountered them and brings them back at a cabin. They are told that if something were to happen to both of them, the snow village will perish. They are taken care of by the women in the village. It was revealed that a male kemono is born only in 100 years until Yui and Akira are born as twins. It is also revealed through his memories that they didn't know what their mother look like and their father was kept isolated and Yui vows to himself that him and Akira will never be like their father's state.

While wondering outside, they find a magazine dropped by a human. At bedtime, Akira tells Yui that he wants to go to Tokyo. Yui agrees for them to go to Tokyo someday and live their life quietly there. During their time of dreaming of going to Tokyo, Yui is chosen as the snow village chief. Yui realizes the thought process of the women of the village on choosing him over Akira and the kind of treatment he will be receiving from there on.

One night, Hisame tries to have sex with Yui, saying that it's been over 10 years since his predecessor become impotent and she's waited for that moment. At bedtime, Yui is silent. Akira asks him if his duties are tough since he come home late and wants to help him. Yui, instead of telling the truth, tells him that it requires a lot of reading and thinking. Hearing this, Akira had second thoughts. Instead, he gives Yui a rare flower he found on a tree and congratulates him on becoming a chief.

Yui then learned different kinds of things as a snow village chief. He is brought to the location of the nil calculus and visits the place when he has nothing to do since it relaxes him. As the days gone by, Yui thinks of himself as filthy.

One day, when Akira and Yui were outside, Akira suddenlly asks Yui if making babies are hard. Yui is shocked to hear this and closes Akira's mouth and asks him where did he hear it, to which Akira replies that he heard it from the women talking. Akira begs his brother to let him do something too since he can't bear seeing Yui struggle all by himself. Yui protects Akira, saying that he doesn't need to do anything since Akira is weak. Though there are some things which Akira is better at, his smile. Yui tells Akira that his smile is his saving grace and tells him not to be filthy and will protect him.

Akira confesses to Yui that he wet the bed. After careful thinking, Yui realizes that if the women learned that Akira had started ejaculating, the women may not uphold the rule of the chief being the only one leaving his seed. He then decides to gather all women of the village and declares to all of them that he will get all of them pregnant, in exchange of Akira leaving the village. Otherwise, he will kill himself. Hisamu refutes saying that if Yui kills himself, they'll just make Akira the chief. Yui then asks Hisame if she had forgotten his body. The women of the village agree to the condition. Yui then intructs Akira to leave the village and look for the kemon office and Inugami.

After a year, Yui realizes that he had been deceived by women and the women sent pursuers to look for Akira. Out of rage, he goes to the location of the nil calculus and calls out its power.

Learning what his brother went through, Akira cries and tells his brother they will share happiness and fun from now on. Kabane rushes to Akira's side and tries to help Akira. He spits out the life calculus. Suddenly, a flash can be seen and Yui regains consciousness. Kabane then sees the life calculus and nil calculus combine.