Gintama is a Japanese comedy anime and manga series centred on Sakata Gintoki, often called Gin-chan, a freelance samurai in an alternate Edo period filled with aliens and parody. Masaka is a common Japanese exclamation meaning that something cannot be true, and Gintoki uses it in moments of comic disbelief. Short reaction clips like this one spread through anime fan edits and soundboards, where a recognisable voice line can carry a joke without context. Its brevity and clear emotion keep it useful for reaction videos and short-form edits.