This is an interesting topic because Mesudachi (メスダチ) sits at a specific intersection of Japanese internet subculture, underground manga aesthetics, and transgressive humor.
In the early 2000s, Japanese net forums invented a word that doesn't exist in dictionaries: Mesudachi . Literally "female animal friend," it describes a best friend who secretly wants to ruin your life. Think Heathers meets 2channel . mesudachi
But the real question: Is there a male equivalent? (Spoiler: No. Because osudachi never caught on.) Think Heathers meets 2channel
What makes it fascinating isn't the misogyny—it's the reclamation . Today, young women in Tokyo use it as a joke: "Yeah, we're total mesudachi. She borrowed my sweater and never gave it back." The term has evolved from a male fantasy of catty women into a self-aware badge of chaotic friendship. Because osudachi never caught on