Ittekimasu is one of the standard Japanese greetings called aisatsu, exchanged at doorways every day, traditionally answered by itterasshai from whoever stays behind. Its literal sense combines going and coming, which is why it carries a promise to return, not just a farewell. Online, the stretched cheerful delivery separated the phrase from routine conversation and turned it into a reusable departure cue on soundboards, anime edits and short videos, where creators need an instantly readable leaving moment without any setup or explanation.