The story-lines are different but both deal with love that slips away. Also both are tear-jerkers. I personally liked Millionaire's First Love better but I still enjoyed both.
Both of these films focus on love that can never be. Ditto has more story to it whereas Classmates doesn't really have an in depth story, but both films are very good.
Both movies are about a high school relationship starting off through text messages. Another similarity is that one half is suffering from a terminal illness while not letting the other person know.
Miyu and Shuya are high school students. They have dated for 2 years. Miyu and Shuya have a promise that no matter what, they will watch a movie together on the first day of each new month. When Miyu and Shuya are on their way to the movie theater, Shuya suddenly cancels their date. Shuya seems like he is hiding something and he acts nervous. Later, Miyu goes to the place where she is supposed to meet Shuya, but she witnesses Shuya getting into a car accident. She panics, but when she wakes up she finds herself on the morning of the accident. Miyu keeps waking up on the day when Shuya got into an accident.
