Fuyubachi
Fuyubachi is an old man who groups up with Zebra and Kamome on the internet and they meet up to commit suicide. They all wear Maromi backpacks so they can pick each other out in the crowd when they meet. He waits with Zebra wondering where Kamome is and is shocked to find that Kamome is a little girl.
It is hinted why Fuyubachi wants to die in the episode. On the train he is saying “Sayo” in his sleep; he is also carrying a Chitose Candy bag that is candy giving to children at seven or three years old. This is a hint that something might have happened to a child named Sayo in his life. The child could have been his grandchild and might have died recently before Fuyubachi could give him/her the candy, or it could have been his own child and he or she abandoned him.