Namco High is a browser-based dating simulation where the player assumes the role of a new student at Namco High, a high school where all of the students and faculty are characters from Namco video games (along with some other properties); the player is one of the cousins from the Katamari Damacy series. The game starts out with the player in detention, having terrorized campus with a giant katamari. While in detention, the player has the option of talking with 18 other characters who have also been sent there. Talking to a character progresses that particular storyline, with the possibility of initiating a romance with them. Though the player can talk to as many characters in detention as they want, the time they have to participate in after-school activities and "date" a character is limited to one per afternoon. After several days have passed the character will be tasked with saving Pac-Man alongside the character of their choice, unlocking one of multiple endings.