上京
じょうきょう · joukyou · JLPT N3 · noun
capital
🚄🗼 上京 = go up (上) + capital (京, as in 東京 Tokyo)
In Japan you always go up to the capital, whatever the direction of travel. 京 is the kyou of Tokyo (東京) and Kyoto (京都). Jou is the on-reading of 上, so joukyou is literally up-to-capital: moving or travelling to Tokyo.
上 — horizontal line above a baseline
上 is an indicative character (指事): a short stroke placed above a longer reference line shows the concept of 'above' or 'up'. The earliest oracle-bone forms used two horizontal lines for this; the modern shape added a vertical stroke for clarity. The core meaning of 'upper, above, to ascend' has stayed stable for millennia.