Sébastien operates a Los Angeles boarding house with his daughter Marie while facing imminent closure due to substantial debts. He possesses curly brown hair and a mustache, typically dressed in a grey shirt beneath a navy apron. During Makoto Edamura's residence, Sébastien shares their financial struggles, prompting Edamura's assistance. He demonstrates a kind and caring demeanor through his supportive interactions and provision of shelter to Edamura throughout this period.