A spectacular three-way simplification: 繁體 圓 / 新字体 円 / 简体 圆 — three completely different visual shapes for the same character. The traditional 圓 has 員 (round person) inside an enclosure (囗); Japanese drastically reduced to a simple frame containing two strokes (円); Chinese kept the enclosure with a simpler interior (圆).

East Asian Currency Convergence: This single character names the currencies of THREE different countries: — South Korea: 圓 / (won) — the Korean Won, abbreviated ₩. — Japan: 円 (en, "yen" in English) — the Japanese Yen, abbreviated ¥. — China: 圆 / 元 (yuán) — the Chinese Yuan, also abbreviated ¥. Modern usage prefers 元 (yuán) on banknotes. All three currency names trace back to 圓 — "round / circle". The original silver coins of imperial East Asia were round, and the character became the unit name. Hong Kong dollar 港圓 and Macau pataca 葡圓 also use this character.

Mandarin: yuán, rising 2nd tone (simplified 圆). 圆 (yuán, circle / round), 圆形 (yuánxíng, round shape), 圆满 (yuánmǎn, complete / satisfactory — "circle-full"), 圆圈 (yuánquān, ring / circle). The currency 元 (yuán) is technically a different character but pronounced identically and considered an abbreviation of 圆.

Japanese: on-reading エン (en) is dominant — 一円 (ichi-en, 1 yen — the small aluminum coin), 百円 (hyaku-en, 100 yen), 千円 (sen-en, 1000 yen — banknote), 一万円 (ichiman-en, 10,000 yen banknote — the highest common denomination). Kun-reading まる.い (maru.i) means "round / circular" — 円い (marui, round). Note まる reads also from 丸 (also "round"); they're visually distinct but semantically overlapping.

The Japanese Yen symbol ¥ goes back to "yen" being romanized from 円 — historically pronounced "wen" or "uen" before evolving to modern "en".

Memory aid: 三 forms — 圓 / 円 / 圆 — circle / yen / yuan / won — one shape, three economies.

In Japan·円 = yen (currency) + round

In China·圆 = round + yuan (currency, but 元 is more common)