Nagisa Hazuki

A first-year student at Iwatobi High School. In the second season, he is a second-year student, and in the third season, he is a third-year student. He refers to himself as "boku." He is 165 cm tall, weighs 55 kg, and was born on August 1st under the Leo zodiac sign. His favorite subject is history, and his least favorite subject is math. He loves strawberry shortcake, strawberry milk ice cream, Western food, sweets, and Iwatobi Surprise Bread, but dislikes natto. He has a unique taste, enjoying dishes like rice balls with protein and meals sprinkled with strawberry-flavored protein. Unlike Makoto, he loves horror and thrill rides. He is the youngest son with three older sisters. He was once a junior at Haruka and Makoto's swimming club and calls close friends like Haruka and Makoto by the last two characters of their names with "chan" attached. After the club closed, he attended a different middle school from Haruka and Makoto, causing them to drift apart. However, he admired Haruka's swimming and wanted to swim together again, so he enrolled in Iwatobi High School.

He has a cheerful and carefree personality. While making free-spirited remarks, he is considerate of those around him. His unpredictable behavior often throws Rei off balance. He is innocent, bold, straightforward, and energetic, serving as the mood maker of the group. After the showdown between Haruka and Rin, he proposed the establishment of the swimming club at Iwatobi High School, appointing Makoto as the captain and Haruka as the vice-captain, while he took on the role of treasurer and actively participated. He successfully recruited his classmate Rei, who he admired for his pole vaulting form and felt a kinship with due to their feminine-sounding names.

His specialty is breaststroke. His swimming style is characterized by a faster time in the latter half, described as a stroke that creates the illusion of his arms extending. His image is that of a penguin, and he himself likes penguins. During middle school, he was forced by his parents to attend a prestigious school, but the mental strain led them to allow him to attend Iwatobi High School. Since then, he has come to dislike studying, scoring in the 90s in history but poorly in other subjects. He even ran away from home to continue swimming but is now working hard to balance swimming and studying. His charm point is his soleus muscle.