There are nine chapters in Ni No Kuni 2: Revenant Kingdom. The game will take you approximately 40 hours to beat depending on the path you take in the game. The game will require you to finish multiple boss fights and story missions, but there is a lot of side content that can be pursued.
Within the nine chapters, players will encounter numerous boss fights and kingmaker battles to progress. However, players can choose at any time to explore the open world of the game, doing activities like Skirmish missions, dungeons, Dreamer’s Maze dungeons, Tainted Enemies, or optional side content through Swift Solutions or other side missions that allow Evan to recruit new citizens to Evermore or earn items.
Upon completing the ninth chapter of the game. Players will have a save created just prior to the final boss battle, which serves as the only way to extend the gameplay experience and tackle quests or side content that wasn’t completed before the conclusion of the game. There is no new game + mode or the equivalent.