Nozomi Fujimiya works as a waitress alongside her sister Wakaba at the restaurant "One Day." Though skilled in kendo, she suffers a severe heart condition that frequently causes collapse during physical exertion, requiring Wakaba's healing. Her special ability generates shockwaves through edged weapons, projecting them several meters.

Nozomi harbors deep guilt over her health, viewing herself as a burden to Wakaba despite their closeness. This bond grows complicated upon discovering they are adopted siblings, with Minamo and Hinata as their biological sisters. Initially adopting a protective knight-like role toward Wakaba in gratitude for the healing, both eventually acknowledge their codependent relationship restricts each other's freedom.

Her development includes confronting romantic feelings for Makoto Okano, attempting a confession during a summer festival that Wakaba interrupts. When Hikari Tsukishiro hospitalizes Wakaba, Nozomi furiously challenges Makoto for siding with Hikari and threatens retaliation if her sister is harmed again, showcasing fierce loyalty and aggressive defensiveness.

In narrative routes focused on both sisters, their intertwined fates culminate in Makoto pursuing a relationship with either sibling. Nozomi's protective instincts intensify against external threats, particularly toward Wakaba. Her background involves adoption after early parental loss, though specific details remain undisclosed.