- “Oh no! I can't believe I left my secret diary lying out! It would be so embarrassing if somebody read that thing...”
- —Bowser, Paper Mario
Bowser's diary is a book that Bowser expresses his feelings in Paper Mario. It can be found while playing as Princess Peach after rescuing the first Star Spirit, Eldstar. The diary is found in the room containing the secret passage to Peach's room. After Princess Peach sneaks out, she and Twink find this diary sitting on a desk. Twink reads the diary for Peach, revealing that Mario defeated the Koopa Bros. and rescued the first Star Spirit, and then reveals the location of the second Star Spirit. Suddenly, Bowser enters the room, realizing that he had left his diary out. After discovering that Peach has snuck out and was reading his diary, he becomes angry, and orders two Koopatrols to take her away. After this, Bowser removes this diary, and it is not seen for the rest of the game.
- Day: ○/○ Month: ☆
- Day: ○/× Month: ☆
- Cloudy then sunny
- Day: ×/× Month: ☆
- Well, the Koopa Bros. got beaten by Mario, diary. He even set free that stupid Star Spirit I kept there. I'm so mad I can barely write! "Ohh, I'm Mario, I'm so big and strong and good and helpful..." I hate him! But I'm not worried. There's no way Mario can save the Star Spirit being held in Dry Dry Ruins. To do that, he'd have to solve the mystery of the sands and then find Dry Dry Ruins in Dry Dry Desert. How would he even know to go to the desert, anyway? So I'm not worried at all. In fact, I'm so calm I'm gonna go to bed now.