Ceaseless Chatterbox Achievement
View 300 skits. Despite all their time together, the party never runs out of things to discuss.There are a total of 320 total skits in the game, but only 300 are required to be unlock and watched for this achievement. You can trigger these as you play through the story by hitting when the icon shows on the bottom right corner of the screen. A faint chime noise will play when one is available to trigger as well. Whenever you see some text down there and the icon, be sure to hit it to begin the skit. You can choose to play it out naturally, speed through it hitting , or skip it entirely by holding . If you choose not to initiate the skit at that time, you can always play it later from the "Reminisce" option at any campfire.
Most of these will pop up naturally as you progress through the story and subquests (some even play automatically), though some will happen when you return to previous areas (usually for subquests, so that'll kill two birds with one stone), and some happen when you complete the training grounds, cook certain meals, find artifacts, fish, etc. Basically anything related to the other achievements in the game tends to have a few skits attached to it.
If you have completed all other achievements and still do not have this, ensure you have completed all trials in the training grounds, cooked each meal in the game with each possible character, and returned to every location in the game after completing the main story at least once. This should round out nearly all of the rest to get you across 300.
Note: Skits that you do not initiate will still get added to the number under Field Guide>Play Record>Skits Triggered in the menu, but do not count toward the achievement until you actually view them. If you have 300+ listed in the record, go through the Reminisce option at a campfire and play anything with a green exclamation point (!) next to it. Once you view all of those, the achievement should unlock.