Kodai Tatta (竜田康大 (たった こうだい)[1], Tatta Kōdai) is a supporting character in Alice in Borderland. He is portrayed by Yutaro Watanabe.
Tatta is a young man of average height and build with shoulder-length dark hair. He always wears a cap, whether on the Beach or outside of it, and he usually chooses shades of blue in his outfit, such as a teal T-shirt and a checked blue and white shirt on top.
Tatta is very friendly and easy-going, he gets along with everyone he meets and is often seen smiling. In the beginning, he was shown paralyzed with fear and unable to escape gunfire during his first game, however, he later proved to be courageous and caring, not scared of fighting against the militants to avenge or save his friends, as well as being able to sacrifice himself to save others.
Tatta used to work as an auto mechanic. His skills were valuable, but he was often careless, putting others in danger. One day, his incorrect placement of a car jack resulted in a car slipping and falling onto his colleague, crushing the man's hand. The man had to quit his job and Tatta was fired straight after. The realization of causing somebody permanent damage became a heavy psychological burden, increased by other colleagues blaming Tatta for the incident. Being called useless by Niragi reminded Tatta of his past, deepening the trauma, which later resulted in his decision to save his friends in a way that could redeem him in his own eyes.