Sara Uchida works as a maid and is the childhood companion of Akiko Hashou. Born into a low-class family, she aspires to a better life despite her status. She has a younger brother, Junichirou Uchida, involved with the Aoba yakuza group; the siblings share a strong family resemblance.

Takao "Taka" Itou first meets Sara when he rescues her and Akiko from thieves, though Sara initially dislikes him. She later develops genuine feelings for Taka, disrupting Akiko's scheme to pair Sara with her own fiancé, Kiyokuni Saionji, freeing Akiko to pursue Taka. Loyal to Akiko, Sara rejects Kiyokuni's advances and quits her maid position seeking independence. Her inexperience leaves her vulnerable in Tokyo's dangerous underworld.

Sara endures severe trauma when yakuza thugs strip her during a gang rape attempt; she escapes by threatening them with a stolen knife. She later reunites with Taka in a beach town, where they share an intimate encounter. Their relationship deepens amidst the social upheaval of 1923 Tokyo.

The Great Kanto Earthquake of September 1, 1923, becomes pivotal. During the chaos, Sara loses her mother. She witnesses Saburou, Taka's sworn brother, die saving her from attackers. Saburou's last words reveal Taka and Junichirou have fled Tokyo, leaving her alone. In the earthquake's aftermath, Sara forms a bond with Kiyokuni Saionji, finding mutual solace and the possibility of a future together.

Sara evolves from a dutiful maid bound by social hierarchies into a resilient survivor navigating love, trauma, and societal collapse. The resolution finds her separated from Taka but building a tentative connection with Kiyokuni, reflecting her journey toward emotional recovery and new beginnings.