Leo Tsushima is the main male protagonist of Tsuyokiss - Cool×Sweet. He is a second-year high school student in class 2-C and a member of the student council. His parents are overseas, so he lives alone in a house that regularly serves as a hangout for his childhood friends Kinu Kanisawa, Shinichi Samesuga, and Subaru Date. Leo is generally portrayed as an average, slightly timid young man who tends to go along with others, earning him teasing from Kinu who labels him a coward. However, this easygoing demeanor is a departure from his past; he was once a hot-blooded and confrontational person who could hold his own in fights, and he occasionally reverts to that fiery side when strongly motivated. His primary motivation in the story is his secret admiration for Erika Kiriya, the student council president, though his feelings are rarely acted upon directly. He also harbors a deep passion for building ships in bottles, a hobby that can make him fiercely protective and even aggressive if someone touches his work. Leo’s role is that of the central male figure, often serving as the straight man to the eccentric personalities around him while also being the catalyst for romantic and comedic situations. His key relationships include his tight-knit childhood friends, who form a group Erika nicknames the Tsushima Family; his cousin Otome Kurogane, a strict martial arts expert who moves in with him to discipline his lack of drive; and a tense, history-laden connection with Sunao Konoe, a transfer student from his middle school past. Over the course of the series, Leo’s development involves slowly rediscovering his inner strength and assertiveness, balancing his timid surface with moments of genuine conviction. He possesses no supernatural or extraordinary abilities, relying instead on his ordinary wits, occasional bursts of physical capability inherited from his past, and a growing willingness to stand up for what he believes in.