Mutsumi, the current lover and former partner of Sasha, is an energetic and friendly individual who does not often let her reservations hold her back. For example, she identifies as bisexual and has been known to flirt openly with Mafuyu, despite feeling embarrassed about it. She met Taisuku shortly after Sasha left Athos and helped him recover from his injuries, earning his trust and love, which she returns in kind. Like Teresa, Mutsumi's primary role is to provide her partner with Soma, but she is also capable of defending herself using a pair of tonfa blades.