Promise at 20 years.

On approaching her 20th birthday, Yuki happily returns to Japan to see her penpal, Junpei. However, Junpei doesn't want to see her as he is the one who had caused her brother's death three years ago. Though the truth reveals one day, Yuki still loves him. The couple finally decides to get married despite the strong objection from Yuki's father and aunt. And just two days before their wedding bells ring, Junpei gets stabbed by his ex-accomplice. To keep his promise, Junpei bears the pain and completes the wedding ceremony with Yuki