When he first appears, Ryo comes off as a typical "tough guy", being a rude loner who tries to keep to himself, though Saki Kimishima later explains that he just has trouble expressing himself.
After becoming trapped in the alternate world, Ryo is the most unnerved by the events. He refuses to accept the reality of the situation and his tough guy façade quickly falls away to reveal that he is actually a coward. He is even scared of his partner Digimon Kunemon, and is disgusted by the Larva Digimon
Over time, his mental state continues to worsen. He becomes paranoid, believing that the others see him as dead weight and intend to use their partners to kill him and he begins desperately clinging to his memories of his mother, begging her to come save him and seemingly forgetting that she was dead. Upon seeing Arukenimon's human disguise, he instantly sees similarities to his mother and begins to cling to her. However, when Arukenimon's true form is revealed, he immediately recognizes that she is not his mother, but this revelation only drives him further into despair.
After being reminded of his mother's death by Haru, Ryo still clings to her memory, believing that he is already dead and the alternate world is the afterlife, and he will see his mother again in there. The Kenzoku take advantage of this and pretend to be a fake version of her with Ryo happily walking to the fake thinking she was real. Depending on route, this does not end well for Ryo.
In the truthful route, Ryo is able to snap out of this depression and delusion and becomes the most level headed member of the group. He calls out both Kaito Shinonome and Shuuji Kayama multiple times for their negative actions and is able to snap them out of their own insecurities, something that the others weren't able to do in the other routes. This essentially makes Ryo the most important member of the group as without him the others all fall into downward spirals in the various routes with these have deadly consequences. Now acting like himself, he has a great relationship with every member of the group and enjoys banter with them. He also finally accepts Kunemon as his partner, realizing that Kunemon is just like him — with this acceptance causing Kunemon to evolve.
Their partnership becomes so strong so fast that he was able to figure out which was the real Kunemon when a bunch of fake ones showed up without effort, something the others struggled to do when confronted by fakes of their own partners. He still retains his fear of Arukenimon though, after everything she had put him through.
