Sei Nagashima raises the championship plaque after his North High Saxons won the CIF Southern Section Div. 7 title last month. The Saxons went on to capture the Southern Regional Div. IV championship.
North Torrance High’s Sei Nagashima doesn’t let a rare blood disorder sideline him from sports.
SPECIAL TO THE RAFU
When North High School recently captured its historic CIF Southern Section baseball championship, center fielder and team captain Sei Nagashima stood at the center of the celebration.
For most people, it was the culmination of a remarkable season. For those who knew his journey, it represented something much bigger.
The championship was the latest chapter in a story defined by resilience, perseverance, and overcoming obstacles that once threatened his ability to play sports at all.
Just two years earlier, Sei had celebrated a CIF championship as the lone freshman on Peninsula High School’s 2023 title-winning team. His older brother Kai delivered the game-winning hit in the championship game at Blair Field, while Sei contributed as a pinch runner and learned what championship baseball looked like from older teammates.
Now, as captain of North’s championship team, he had come full circle. A two-time CIF Champion. But unlike 2023, when he was the freshman learning from older teammates, this time he was one of the leaders helping write school history.
Long before championships, however, there was uncertainty. At the age of six, Sei was diagnosed with chronic immune thrombocytopenia (ITP), a rare autoimmune blood disorder that causes dangerously low platelet counts. For a young boy who loved sports, the diagnosis raised difficult questions about whether he would be able to continue competing.
Doctor visits, treatments, countless needles, and uncertainty became part of everyday life.
His condition was so rare at his young age that UCLA Health featured Sei’s journey in a 2023 story highlighting how he continued to pursue athletics while managing the disease.
Sei and his family refused to let the diagnosis define him. Instead, it became the foundation of the resilience that would shape every challenge that followed.
Sei learned to manage his blood condition so he could simply keep playing the sports he loved — baseball and football.
In the summer of 2025, he joined the North football program. The fresh start gave him new confidence, new friendships, and a new opportunity. After a half-season transfer sit-out period, he entered the lineup midway through the season and immediately earned a starting role in North’s defensive secondary.
Then adversity struck again.
Just two weeks after returning, Sei completely shattered his left index finger. Doctors believed reconstructive surgery would be necessary and assumed his season was likely over.
Sei wasn’t ready to stop playing. He taped the finger and continued competing, helping North reach the playoffs and earning the football program’s prestigious Hammer Award, presented to a player who exemplifies toughness, leadership, work ethic, and resilience.
His coach would describe his injury as one of the most gruesome hand injuries he had ever seen, “but Sei kept playing.”
Few days after the season, Sei underwent reconstructive surgery. Within eight weeks, he was back participating in baseball activities while continuing his recovery.
As North’s center fielder and team leader, Sei helped guide the Saxons through one of the greatest seasons in school history, culminating in a CIF Southern Section championship.
His playoff performance reflected the player he had become.
In the opening round, he went 3-for-4. In the semifinals, he never recorded a hit, yet still found a way to impact the game: four plate appearances, two walks, one hit-by-pitch, a sac fly for a RBI, two runs scored, and a stolen base.
In the championship game, he reached base four times and finished 2-for-2 with two walks.
For Sei, it was another full-circle moment. Two years earlier, he had celebrated a championship as a freshman while watching his older brother deliver the game’s biggest hit.
Now he was helping lead a championship team of his own. But this time, he wasn’t standing in anyone’s shadow. This time, he wrote his own story.
Despite the championship, Sei’s journey is far from over. He continues to manage chronic ITP while preparing for his next goal: beginning the process of entering the El Camino Fire Academy to become a paramedic technician firefighter.