Upa and Liang appear to have mutual respect for one another. Liang often bickers with Upa over who is next to spar with Samon. It was later revealed that Liang and Upa used to be under Hachiman. Upa seems to care for Liang's well-being as he helped Liang defeat Rokuriki, a guard that was being controlled to attack them.
A fellow cellmate. Upa sees him in low regard, often calling him trash. He also refuses to have Qi touches the cactus his family bought for him, saying that the cactus will become trash if Qi touches it. He also was extremely annoyed that Qi had his hair color, saying that it was a disgrace. Despite this, Qi and Upa seem to be on good terms which, however, it worsened when Qi chose to join hands with Enki. It was later revealed that Qi was pretending to join hands with Enki and was trying to free Upa and Liang. It was also revealed that Qi donated his organs to Upa when Hachiman sold Upa's organs away. Upa feels grateful to Qi for donating his organs but was angry that Qi decided to move on his own to save both him and Liang.
Upa always seemed to be annoyed by Nico's enthusiasm about his qigong abilities; it seems as though Upa felt Nico thought it was not something that should be treated seriously. However, after the New Year's Tournament Upa seems to be more tolerable of Nico.
In further episodes Upa seems to be worried about Nico and his health condition. Battling with Hachiman, he was even afraid to use qigong while Nico was nearby, because he knew that Nico could die if he will repeat his technique.
Upa admires Samon's talent and strength, often asking him to spar with him. He often bicker with Liang to spar with Samon. Upa is also grateful towards Samon for telling his family that Upa was alive and well.