Kei Tachikawa is the A-class leader of Tachikawa Squad (A-rank #01) and Ranked #1 attacker. He's Jin's rival and friend.
Tachikawa is an arrogant person. He acts like Jin and both have a similar way of thinking, which makes him unliked by Miwa, who he likes to tease. Despite that, he's quite friendly outside the battlefield. While Tachikawa is arguably the most skilled Border combatant and a competent leader, his skills outside of fighting are quite lacking. He's not particularly clever and his grades are said to be average at best.
(Source: World Trigger Wiki)
