Okada Ryouko

An English teacher at a private high school. She had a romantic relationship with one of her students, and eventually married him after he turned 20. They dated for 4 years, and lives together as a married couple for 2 years. She's a wife who dotes on Yuuta like an older sister, which worries Yuuta a lot.

Yuuta had an accident while riding his motorcycle, and the owner of the car he crashed on demands a large sum of money from him. Because of that, Ryouko decided to secretly work at "Ubai".