A daily life dominated by my sister-in-law's intense sexual desire. Despite her tsundere personality, the moment her husband leaves for work, she begins seducing me. She deliberately masturbates in front of me, spies on our marital relations, and constantly tempts me with provocative actions. When she sneaks into my room as I'm about to sleep, our relationship escalates rapidly. Unable to resist her advances, a new boundary is crossed between us.