Kaori Sakuragi
Kaori Sakuragi was a young girl who came to attend Miator starting off in her first year. Ever since she was young, Kaori has been physically weak due to an affliction which remains unnamed, but apparently affected her breathing and possibly her heart. She had a placid personality, and dealt with her condition with surprisingly good grace. Spoiler Upon arrival at Miator, she was entrusted to Miyuki and Shizuma in order to look after her and make sure she had a worthwhile experience while at the school. Eventually, Kaori and Shizuma formed an intimate relationship, which is why when Shizuma entered to become the next Etoile, she chose Kaori as her partner. However, by the time they both had become Etoile, Kaori's body had deteriorated too much and before long she passed away, leaving Shizuma with a broken heart. (Source: Wikipedia)