Kaoru Komatsubara is a minor character from the original Cardfight!! Vanguard anime, primarily appearing as an opponent during the regional tournament arc. He is a male teenager with blue hair cut to ear length and orange eyes, often seen wearing a bandana, shorts, boots, and a t-shirt. Kaoru participates in the regional tournament finals as a member of an opposing team, where he is scheduled to fight Toshiki Kai in the second match of the finals. He carries himself with a confident, boastful attitude, frequently mentioning his past experience as a national-tournament-level player, which he believes makes him a skilled fighter. During his cardfight against Kai, he demonstrates a competitive spirit and a desire to prove his abilities, though his arrogance is met with Kai's calm and analytical approach. Kaoru has a distinctive vocal tic or catchphrase that sounds similar to ka-boom, which he exclaims during his fight. As a cardfighter, he is competent enough to reach the tournament finals, and his strategy involves using his grade 3 vanguard and spending two counterblasts to resurrect two monsters from the drop zone to his rear-guard. He also encourages his teammate Aichi Sendou by telling him to "image shiro," urging him to visualize his plays. Despite his confidence, Kaoru loses decisively to Kai when Kai rides Blazing Flare Dragon and draws two critical triggers on his final turn, dealing a finishing blow that Kaoru cannot guard against. The loss serves as a turning point for Aichi, who observes the match and finds renewed motivation to fight after witnessing Kai's overwhelming strength. Kaoru does not appear as a recurring character beyond this tournament arc, and his role remains limited to this single significant cardfight.