After experiencing the grief of losing Sabo, Luffy and Ace made a vow on the seaside that one day they would go to sea, become pirates, live without regrets, and become the freest people in the world. After this the D brothers lived together at Mount Kolber for seven years. The story begins on the last day of the year and ends when Ace goes to sea at the age of seventeen. During this period, I experienced holding hands, first kiss, and gentle pushing. That's probably it.