Although Misao and Tsunayoshi are not biologically related, they consider themselves siblings. Tsunayoshi, who was previously a delinquent, has transformed into an affectionate brother who frequently embarrasses Misao. Nonetheless, when they are faced with peril, he demonstrates his devotion by putting his life on the line to safeguard hers. This unwavering devotion reveals an illicit romantic connection between two individuals who are not bound by blood.