What are some of the most unusual sequels to beloved JRPG games?

For me it is Kingdom Hearts 358/2 days to the Kingdom Hearts games at the time of its release. I do not think that it is bad game but it felt so different compared to rest of the Kingdom Hearts games that I played at the time. What makes it so usual is how the game follows a mission structure as opposed to the usual sandbox structure of previous games. Chrono Cross is another one when you consider that Trigger was an adventure while the sequel was more contemplative.