Poppo is the first friend that Jinta reconnects with. As a child, Poppo was uncontrollably energetic and friendly and was always loyal to Jinta recognizing him as the leader of the group. These traits have not changed. Presently, Jinta reunited with him when he was searching for Menma. He visited their old clubhouse and found that Poppo was living there. Poppo explains that he works part-time jobs to earn money. When he makes enough, he goes on trips around the world. Because of this, Poppo has not attended school in several years.

Poppo seems to have questionable interests: Jinta found several pornographic magazines upon entering the clubhouse. Poppo also seems to have an obsession for foreign girls, especially Vietnamese girls. Overall, he has a lewd personality.