Paper Mario/Chapter 1: Storming Koopa Bros. Fortress

Mario and Goombario continue the journey on Pleasant Path. They battle a lot of Koopa Troopas and Goombas until they find a river with no bridge. Mario uses the hammer and reveals a switch. He presses it and a bridge pops up. Mario and Goombario cross it and continue their journey. They go to Koopa Village first.

The Fuzz(ies)
Mario and Goombario enter Koopa Village. A Koopa Troopa tells you the Fuzzies are attacking. Then a Fuzzie catches the shell of the Koopa Troopa. He chases the Fuzzie but you must get the shell back and give it to the Koopa Troopa. You must also help other Koopa Troopas get their shells back. Now the town is saved. You must also find the blue-shelled Koopa named Kooper. Kooper will ask you to get the shell back from the King Fuzzie. You must go into the house, but there the King Fuzzie will get away. Chase the King Fuzzie to his hideout. The King Fuzzie challenges you to find him in one of the trees three times. If you pick the wrong tree, the King Fuzzie's underlings will appear. If you pick the right tree, King Fuzzie will appear. You must find the King Fuzzie three times and successfully catch Kooper's shell. Kooper then joins your party. Then King Fuzzie and his three underlings will battle you. You must defeat them to continue your journey.

Another Hassle in the Other Castle
You have successfully found your way through Pleasant Path and found the fortress. The Black Ninjakoopa will spot you, and then run into the fortress. Go into the fortress and defeat the Koopa Troopa to receive a key. Unlock the door and go into the next room. You face Bob-ombs. Defeat them. Then Green Ninjakoopa appears. Green puts keys behind some gates and then runs away. You now face Koopa Troopas and Bob-ombs. Defeat them to unlock doors in the fortress. You then find Yellow Ninjakoopa. Yellow sets a trap and then runs away. You will fall into a prison cell. Here you meet Bombette. She tells you that she has a lot of power. Bombette joins the party and gets you out of the cell. Go through the fortress until you find the Koopa Bros. Red Ninjakoopa gets his brothers to fire Bullet Bills at you. Battle them to clear the fortress. "Yes, lets do what the narrator says, battle them to clear the fortress," said Mario.

Peach: The Diary of a Koopa King
Walk to the painting in Peach's room, press it to reveal the fireplace as a secret passage! Use it and you'll find yourself in Bowser's room. His diary is on the table, revealing the location of the next star spirit.