Koushiro Izumi Male 17 years old Your childhood friend of 8 years. He is incredibly intelligent. Compared to Joe Kido, who is also an intellectual character but somewhat indecisive, Koushiro possesses a wealth of knowledge practically useful for adventures. His calm personality makes him a vital asset to the group, holding a very high weight in their overall strategic power. Consequently, he is deeply trusted by Taichi and the rest of the team. His thirst for knowledge is immense; when Vademon stole his curiosity, Tentomon de-digivolved, leading Koushiro to realize that he isn't himself without his intellectual drive. However, once he becomes curious about something, he tends to lose sight of his surroundings and can be indifferent to his companions' feelings, which once made Mimi Tachikawa cry. He also has a tendency to judge things solely based on knowledge. In the late 1990s and early 2000s, it was remarkable for an elementary student to be so curious about and proficient with various electronic devices. In the series, Koushiro is often seen manually inputting program commands into his computer. Leveraging his innate talent for computing, he established a fairly large company by the time of the Last Evolution Kizuna events. He likely inherited his genius from his biological father, who was a brilliant mathematician. Perhaps because of this, the triggers for his partner Digimon's evolution differ significantly from the other children. While others, being mentally immature, evolved their partners to the Champion level through mental growth during counterattacks against enemy Digimon, Koushiro triggered the evolution using a program he obtained from a factory, involving no immediate mental growth. Similarly, for Ultimate evolution, while other children needed trials to regain lost childhood virtues, Koushiro had never lost his defining trait—curiosity. Thus, his story involved a Digimon forcibly stealing his emotions and him having to reclaim them. It wasn't until the Mega level that he underwent traditional mental growth to trigger an evolution. Though recognized as the best brain in the Digimon series, he showed an unexpected weakness in foreign languages in 02, unable to speak a word of English when visiting Hong Kong. However, by his first year of high school, he has mastered mechanical engineering, electronic engineering, and computer science at a level that rivals university professors, and he can even speak French. Given his established ability stats, this level of competence is fitting.