Upon their first meeting at the Kyoto Fushimi Cycling Club, Midousuji challenged Ishigaki to a race to claim Ishigaki's position as the ace. Midousuji won their race. Midousuji treats Ishigaki as just another one of his mass-produced teammates despite Ishigaki being the captain of Kyoto Fushimi. He would initially become irritated whenever Ishigaki would step out of line, such as Ishigaki's habit of accidentally forgetting to add the -kun suffix to Midousuji's name. Beyond the second day at the 41st Summer Inter High, Midousuji allowed Ishigaki to drop the suffix and lets him call him just "Midousuji." After Ishigaki expresses how he feels pride in being Midousuji's assistant, Midousuji calls him "too gross"- a response to not being able to understand why he warmed up to him so much.
Midousuji believes that the "underhanded technique" he used during their middle school race was nothing more than a test to see how prepared Imaizumi was for any possibility during a race. Since telling Imaizumi that his mother died caused him to fall behind, Midousuji deemed Imaizumi weak and refers to him appropriately as "Yowaizumi-kun." The two of them harbor varying degrees of distaste for one another. Throughout the entirety of the 41st Summer Inter High, much of how Midousuji treated Imaizumi stemmed from his belief that Imaizumi was nothing more than a prideful, "third-rate" cyclist, and that he wasn't a worthy opponent. Midousuji frequently tore into Imaizumi with harrassment and toyed with his desire for revenge in an attempt to crush his will to ride. Come the third day, Imaizumi had grown to a point where nothing Midousuji said or did fazed him. Midousuji was frustrated with Imaizumi's personal growth, and responded childishly by upping his antics until he ran out of energy.
Midousuji encountered Onoda on the first day of the 41st Summer Inter high when Onoda needed to pass 100 cyclists to reunite with Sohoku. Onoda exceeded Midousuji's expectations in that moment, leading Midousuji to decide that he's not just another "mass-produced model". After the second day, Midousuji and Onoda met on Midousuji's way back to Kyoto. Onoda surprised Midousuji by asking him about anime rather than prodding at his performance as a racer, and the two raced to the pharmacy with Midousuji taking first place. Upon asking what motivates Onoda to ride, Onoda replied that cycling is fun, and that he gets eager to ride with others. Midousuji called it gross and couldn't understand his answer because it seemed too simplistic. At the end of the third day, Onoda caught up with Midousuji and Manami. Onoda claimed it was because he was thinking about them ahead of him. Midousuji became amused and began calling him "Sakamichi" after Onoda kept up with them. Midousuji still doesn't understand the reasons behind Onoda's smile or the limit to his growth and capabilities, and can't figure out how a person like Onoda, who doesn't strive for victory, could ever win.
On the last day of the Inter High, Manami challenges Midousuji to a race that "uses all five of the senses" to determine who was faster. Midousuji notes that although both Onoda and Manami smile when they ride, the latter's smile is different. As they race, Manami asks Midousuji if he feels alive in class, proceeding to explain how he loves cycling because he feels alive when he's closest to death, referring to how he exerts all the strength in his body to overtake his opponents when racing in a close battle. Manami is currently the first and only person Midousuji has stated "isn't gross" in acknowledgement of his strength. They are also both depicted as having metaphorical wings during their race, with Manami's white and Midousuji's dark.
While Midousuji never had much to say about Naruko, but doesn't like his extravagant riding style , but after Inter High, he went to Osaka to challenge Naruko on his home track, since Naruko already won 2 3-lap gauntlet races, Midousuji challenged him to a 10-lap 6km race, but with Midousuji winning, Naruko must become an all-rounder, as per a one-sided bet by Naruko's own design.