Azukiarai (小豆洗い lit. azuki bean washing) is one of the temporary settling Another in the area of Shinjuku Ward Kabukicho. He harmless but his constant change of locations gives the staffs of Nocturnal Community Relations Division a hard time in looking for him.
It is said that it will appear in the riverside and in the mountains, make sounds, and sharpen the azuki beans at Another known throughout Japan. In some areas, witnessing this is considered auspicious as a sign of marriage.
Azukiarai is a cannon character which means it's an original character in the anime series.