It has been 1 year since after hearing Ken's confession, Rei left Tada during their wedding ceremony. Although Ken and Rei knew how they felt for each other, they were still unable to take a step forward.
At the same time, Eri and Tsuru's wedding was about to go on in Hawaii, so Ken, Rei, Mikio, and the others went to the church on the beach. However, as the time slowly passed read morethe time of the ceremony, it had yet to begin. While Tsuru desparately tries to cover this fact, everyone finds out that Eri is in fact missing. When he awoke this morning she had been missing, and only a hand written note was left behind saying that she "Doesn't know how Tsuru feels". -dramawiki