I Want to Protect That Smile is a popular catchphrase and reaction image used to express deep affection for a character's innocent or joyful expression. Originating from anime and manga culture—specifically associated with tropes found in visual novels and series like Fate/stay night—the phrase quickly transcended its otaku roots to become a staple of wholesome internet culture. It is typically used when a character who has endured hardship shows a rare moment of genuine happiness, prompting fans to declare their protective devotion. While usually used sincerely to highlight heartwarming moments, it is occasionally applied ironically to characters who are secretly dangerous or to 'blursed' images, making it a versatile template for both fans and shitposters alike.