Yuri Uehara is the sister-in-law of Hisashi Uehara, married to his older brother Takuya. Her marriage to Takuya profoundly affected Hisashi, who had nurtured a six-year romantic crush on her but ultimately stepped aside for his brother. This unrequited love contributed to Hisashi's departure from the family home.

Her personality is carefree and kind, though marked by a tendency for excessive shopping. Alcohol significantly alters her behavior; intoxication transforms her into a "kissing monster," leading her to kiss people indiscriminately. She sometimes uses alcohol to cope with emotional distress, including marital conflicts.

Yuri forms a close bond with Nao Yoshikawa. Amidst marital strife with Takuya, she announces divorce plans and moves temporarily into the apartment shared by Nao and Hisashi, forcing Hisashi to return to his family home while she stays with Nao. Reconciliation with Takuya follows, facilitated by Nao's intervention after Yuri angrily discards her wedding ring.

Her presence propels Hisashi's character development, stemming from their past unrequited romance and later through the shared living situations arising from her marital conflicts.