Saika Totsuka attends Sobu High School as a member of Class 2F and presides as the Tennis Club president. His strikingly soft, feminine appearance frequently causes mistaken identity, notably by Hachiman Hikigaya. He features short, light grey or silver hair, large blue eyes, and light skin sensitive to sun exposure. He typically appears in his gym uniform, often carrying a tennis racket with a towel draped around his neck. His anime outfit includes a dark and light green sports jacket, matching shorts over black knee-length tights, and a lighter green V-neck long-sleeved shirt. Light novel depictions note a light blue jacket later replaced by green, worn with a short-sleeved white undershirt sporting a blue collar. He consistently wears a black bracelet on his right wrist. Academically, Saika shared a first-year class with Hachiman Hikigaya, though Hachiman initially failed to recall this. His parents named him "Saika" hoping his life would "add colour to others." As Tennis Club captain, he displays strong leadership and similarly led the red team during the school's Bo-Taishi event, motivating teammates through perceived "cuteness." He dedicates lunch breaks and free time to rigorous tennis practice, showing marked dedication. He also possesses keen observational skills, recognizing Hachiman's stress through careful attention, and demonstrated acting talent in a Cultural Festival class play. Personality-wise, Saika embodies kindness, gentleness, and peacefulness. He avoids conflict, maintaining harmony even when pressured, such as silently conceding the tennis courts to Miura. Despite feminine traits earning him the nickname "The Prince" from female classmates, he consciously attempts more masculine behavior and expresses discomfort over gender mistakes. Sociable and free of resentment, he interacts easily with others, often blushing, particularly around Hachiman. He enjoys horror movies and haunted houses but dislikes scary stories. His fondness for rabbits is noted, finding them cuter than dogs or cats. Saika first appears in Volume 1, approaching the Service Club for tennis improvement help after encountering Hachiman and Yui Yuigahama during lunch. He partners with Hachiman in gym class tennis, inviting him to join the club, an offer Hachiman declines. A practice injury leads to a tennis match between Hachiman/Yukino and Hayama/Miura for court access, refereed by Saika. He later joins Hachiman and Hayama's group for workplace tours after hinting his preference to Hachiman. He assists the Service Club with various requests, including efforts to aid Kawasaki Saki, though excluded from a hotel visit due to inappropriate attire. Noticing Hachiman's low spirits during Yui Yuigahama's temporary absence, Saika invites him to an arcade. His feminine appearance allows them access to a couples-only photo booth; he later gives Hachiman a photo from their outing. In a Drama CD side story, he attends Yui's birthday party, leading a toast and offering to cut the cake. His relationship with Hachiman is significant. Saika consistently treats Hachiman with kindness, using his first name. He is among the few with access to Hachiman's phone number and email. Hachiman never speaks ill of him, verbally or mentally. Their interactions sometimes cause Hachiman to momentarily forget Saika's gender. Saika actively shows concern for Hachiman's well-being, organizing outings to cheer him up. He stands as one of Hachiman's genuine friends, alongside Yoshiteru Zaimokuza. Beyond the source material, Saika participated in the International Saimoe League (ISML), debuting in the 2016 main tournament. Following Hachiman's ISML championship win in 2018, Saika became a primary male representative for the series. He secured the Amethyst exhibition ring in 2020 and qualified for playoffs in both 2020 and 2021.