My Rainy Days (2009)

17 year old high school student Rio is always the center of attention due to her beauty. Yet, Rio has never cared about anyone but herself due to her traumatic past. Her friends and boyfriends exist only so she can use them for her gains. Rio is only interested in money. Then one day she meets 35 year college professor Kouki and falls in love for the first time. Rio feels confused by her emotional change and expresses her love to Kouki honestly. Although Kouki becomes interested in Rio there is a reason he can't pursue the relationship. Based on the popular cell phone novel of the same name.