Sōma Shiki is a 19-year-old design student whose youthful look frequently leads to him being mistaken for a high schooler. He sports magenta-dyed hair that matches his magenta eyes, three piercings on his left ear accompanied by a small triangle tattoo behind it, and a single piercing on his right ear.

Naturally accepting and positive, Sōma often laughs off his own clumsiness instead of fixating on mistakes. Yet, beneath this optimism, he harbors quiet insecurities about lacking the necessary "weapons" – confidence or skills – to decisively pursue his design career aspirations. He shares an apartment with his older brother, Sōta Shiki.

Sōma works part-time as a waiter at Mawarimichi café under the mentorship of Asami Futami, who teaches him cooking. During his free time, he enjoys photography, often capturing scenes in local parks. His approachable nature shines in his interactions: he met Hayate Ichikura ("Hayate-kun") outside the café, encountered Shun Futami ("Shun") while photographing in a park, connected with Takayuki Mima ("Mima-san") when retrieving his brother after an outing, and formally befriended Motoharu Igarashi ("Motoharu-kun") at a movie theater after an initial casual meeting during a park walk.

His name carries personal and familial meaning: "Sōma" (蒼真) combines "blue/pale" and "genuine," while "Shiki" (四季) signifies "four seasons."