Wife-in-law lesbian training

Six months after getting married...my father-in-law suddenly died. Yuna has come to live with the Shoda family to take care of her mother-in-law, Chisato, who lost her husband. Senri's eccentric behavior was beyond Yuna's imagination, and it escalated day by day, including incontinence, wandering, and lying. One day, Yuna sees Chisato masturbating alone and tries to stop her, but she is mistaken for her late husband and raped. Lesbian training begins that day... However, Yuna has no way of knowing that this is an obscene desire that lies a thousand miles away from oblivion...