What is “Momesa”? Meaning and Origin of the Japanese Internet Slang

“Momesa” is an abbreviation for “Momesase-ya” (揉めさせ屋), a term used to describe a person or behavior that disrupts a space or incites conflict.

The term “Momesase-ya” is a combination of two Japanese words: “Momesaseru” (to cause trouble or stir up conflict) and “Ya” (a suffix meaning someone who does a certain thing). While “Ya” is often used for shops like “Sushi-ya” (Sushi shop) or “Ramen-ya” (Ramen shop), in this context, it refers to a person who performs a specific action.

While mostly seen on the internet, it is also occasionally used in real-life settings such as workplaces or local communities.

Many “Momesa” intentionally cause trouble to enjoy the resulting chaos. However, some people become “Momesa” unintentionally without any malice. Since the term refers to someone who triggers conflict, it is almost always used in a negative sense and has no positive connotation.

Common Phrases and Usage:

• That pattern is definitely a momesa.
• Whether they are a momesa or not isn’t the point.
• It was obvious that they were a momesa.
• Is that guy acting like a momesa here, too?
• Did you tell such lies just to act like a momesa?
• Their behavior is completely that of a momesa.
• “Hato” and “Momesa” are pretty much the same thing.

The term originated on popular Japanese internet message boards like “5channel” (formerly 2ch) as the internet became more widespread. While the exact origin date is unclear, it existed as early as 2007 and gradually began to appear more frequently in the 2010s.

As of 2026, it is not a term used every day, but its visibility on social media (SNS) is increasing. It is expected to continue spreading slowly in the future.

Related Slang: “Hato” (Pigeon)
A similar term for someone who causes trouble is “Hato” (Pigeon), or “Densho-bato” (Carrier Pigeon). Mainly used in the live-streaming world, it refers to users who report what other streamers said—often exaggerating or sharing unnecessary information (e.g., “The other streamer said XYZ about you”). Pigeons who tell lies are specifically called “Uso-hato” (Lying Pigeon).