Ruriko Tonegawa appears in the "Hidden in the Pottery" story within the Rumiko Takahashi Anthology. A young widow after her husband's fatal car accident, she shares her apartment with her mother-in-law, resulting in a tense home life.

Neighbors observe the elderly woman's frequent injuries and Ruriko's apparent lack of grief at funerals, suspecting Ruriko of abusing her mother-in-law. This suspicion intensifies when neighbor Yukie Asakawa finds bone fragments concealed within flower pots Ruriko entrusted her with. Yukie confronts Ruriko, accusing her of hiding her mother-in-law's remains.

Ruriko's backstory reverses these assumptions. She reveals her mother-in-law presented a kind public face while subjecting Ruriko to private psychological abuse, which worsened after her son's death. The discovered fragments were actually her husband's bones. Ruriko hid them in the pottery to keep his remains close while enduring her mother-in-law's dominance, planning a proper burial later—an act born from her need for connection amidst ongoing mistreatment.

Her character development hinges on this revelation of hidden suffering. Actions initially perceived as malicious are recast as responses to prolonged domestic abuse. The narrative concludes with Ruriko preparing for her husband's formal burial, marking a step toward resolution after her experiences come to light.