Normal restrictions apply to cards exiled by Ornate Kanzashi (you can’t cast an instant unless you have priority, etc.).

Cards exiled by Ornate Kanzashi’s ability are exiled face up.

You must pay all costs to play cards exiled by Ornate Kanzashi.

You can’t play cards you exiled with Ornate Kanzashi on previous turns.

Cards exiled by Ornate Kanzashi’s ability stay exiled even if the Kanzashi leaves the battlefield.