Kingdom Hearts II is set how long after Chain of Memories?

Kingdom Hearts II is set one year after Chain of Memories.

The time gap follows the events of both the original Kingdom Hearts and Kingdom Hearts: Chain of Memories. After the Chain of Memories storyline, Sora, Donald, and Goofy spend a year asleep in Castle Oblivion so their memories can be restored.

That long sleep explains why Kingdom Hearts II opens with Roxas, Sora's Nobody, as the playable lead in a simulated Twilight Town. Roxas's opening chapters gradually reveal what happened during the gap and lead into Sora's return. The structure lets the sequel acknowledge Chain of Memories while giving new players an introduction to its consequences.

A common misunderstanding is to treat Chain of Memories as a side story separated from Kingdom Hearts II. It is actually a direct bridge between the two games: its events introduce Castle Oblivion, Organization XIII, memory manipulation, and the year-long restoration process that defines the sequel's opening.