Izumida introduced his childhood friend, Kuroda to cycling, however, Izumida is a very smart student with poor athletic ability in general, be it in baseball or cycling.
As a first-year at Hakone Academy, Izumida didn't perform well during practice, falling behind his fellow first-years despite how hard he trained. One day, Fukutomi Juichi told him that "you don't move a bicycle with your legs", and that Izumida no longer needed to ride anymore. Feeling that the's words meant he was being kicked off the team, Izumida resigned himself to this fact. However, Shinkai Hayato told him that he'd misunderstood Fukutomi, who tended to always terrify underclassmen by saying and expressing little, and that Fukutomi was in truth telling him to work on his skills outside of riding. Shinkai complimented Izumida's muscular body, and said that everyone has a weapon, they just need to find it and refine it. Izumida took this as meaning he should work on building his muscles and trained his body rigorously from then on.
Prior to his first Inter High, Izumida increased his weight by eating a substantial amount of food, and then transformed all the fat and calories into muscle by intensively training. When he returned to cycling, even though his results in races before then were mediocre due to his diet, Izumida finally excelled at sprinting and earned his place as the fifth member of Hakone Academy's Inter High team.
Building Hakone Academy's Cycling Team
F-Group Selection Race
On Day 3 leading up to the final climb before the goal, he manages to pull his team to over 500m ahead of Sohoku with a 4-6 shorthand before dropping out; Shinkai congratulates him on his efforts, and Izumida thinks of how proud he is to be riding with Shinkai.
In the resting tent after the race, he hears of Hakone Academy's loss and begins crying, but Arakita tells him to stop as he has to think ahead for next year.
After the Inter High
Izumida appears very briefly at the end of the film when he bursts out of the sauna at Toudou's family inn, shouting "Abs!"