TV-Series
Description
Koh Grif is the younger brother of Sho Grif, both heirs to the Grif Financial Group. This fifth-grade elementary school student, approximately 11 years old, possesses an unusually muscular and imposing physique that belies his age. He sports spiky blue hair fastened with pink clips and striking yellow eyes, typically wearing a white uniform with blue linings identical to his brother's attire.

Koh's appearance transforms dramatically alongside his Guardian Bakugan's evolution. When his Haos-attribute Kilan Leoness evolves into Shield Leoness, Koh dyes his hair blonde and changes his uniform linings to yellow. After Shield Leoness evolves further into Ogre Leoness, he reverts his hair to blue while keeping the yellow-lined uniform.

Initially displaying a haughty attitude, Koh underestimates others, challenging Harubaru Hinode with overconfidence. Defeat prompts him to acknowledge Harubaru's strength, apologize, and form a friendship. This marks a turning point where Koh begins valuing connections and mutual respect over dominance. He later teams up with Harubaru, Raichi, and his brother Sho to form Team Dragaon.

In battle, Koh relies on immense physical power, specializing in the defensive "BakuTech Lion Rock" shooting skill. His Bakugan, Kilan Leoness, is a "Defense and Occupied" type, making it difficult to dislodge from Gate Cards. Despite this strength, his aggressive tactics often lead to him being overpowered, resulting in frequent losses; he secures only one victory across five anime battles.

Koh holds deep respect for his older brother Sho, whom he addresses as "Aniki." Their relationship shows strong loyalty and mutual support, evident when Sho becomes enraged after Tohga overwhelms Koh and crashes him into a wall. Koh refers to himself in the third person as "This Koh Grif" in the manga and uses "Waga" in the anime, preferring "Omae" as his second-person pronoun.

His development includes enrolling at the Bakugan Dojo with Sho to hone his brawling skills and participating in events like the Tavanel Cup with Team Dragaon. Koh's journey shifts from isolated arrogance to collaborative growth, though his core traits of pride in his abilities and unwavering familial loyalty remain constant.