往復
おうふく · oufuku · JLPT N2 · noun
round trip
🚆🎫 往復 = go (往) + return (復): a round trip
往 means to go toward, as in 往く (iku, to go). 復 means to return or repeat, as in 復習 (fukushuu, review). Going plus coming back gives a round trip, or a return ticket: 往復切符 (oufuku kippu).
往 — 彳 (step radical) + 主 (phonetic)
往 originally depicted a foot moving toward a place, with the 彳 radical signaling motion or walking. The right component 主 served mainly as a phonetic clue. Over time the meaning settled into 'to go (toward)' and, by extension, 'past' or 'previously'.