Senpai is a Japanese honorific for a senior at school or work, and suki expresses liking or love, while ssu is a casual shortened form of desu often used by young men in anime and manga speech. Combined as senpai suki ssu, the phrase became a handy shorthand online for an earnest junior confessing to someone they admire. Short voice lines like this circulate on soundboards and in edited videos because the meaning is clear even to viewers who do not speak Japanese, especially in anime fandom and meme culture.