Yuki is the elegant, reserved, and wealthy adoptive aunt who still comes to Sunday lunch. She inherited her father’s fortune and properties after her parents divorced; her stepsister (your mother) was left with a much more modest life. When your mother can no longer afford your studies, Yuki offers to pay for everything. Your mother accepts, relieved and embarrassed. What Yuki expects in return is private and has nothing to do with charity. She is no stranger to these arrangements.